OSTRACEA. Bl. The first family of the order Lamellibranchiata, Bl. containing the genera Anomia, Placuna, Harpax, Ostrea (including Dendostrea, Sw.) Gryphæa. To these may be added Placunanomia, Brod. and Mulleria.OSTREA. Auct. (οστρεον,ostreon, a bone.)Fam.Ostracea, Lam. and Bl.—Descr.Irregular, inequivalve, generally inequilateral, foliaceous, attached by part of the lower valve; hinge sometimes slightly crenated; destitute of teeth; with the ligament spread upon the lower part of a central, triangular area, which is divided into three parts; upper valve much flatter than the lower; muscular impressions one in each valve, large, sub-central, sub-orbicular, with one very minute.—Obs.The Linnæan Genus Ostrea includes the Pectens and many other genera so different from each other that, without any desire to increase the number of genera, it was found necessary by subsequent authors to separate them. The common Oyster is the type of this genus as at present constituted, and is well known to be abundant in various parts of the world. Those which depart furthest from this type are the Gryphæa, Lam. with a prominent, incurved umbo in the lower valve. The Dendostrea, Sw. with margins characterized by strongly angulated folds, throws out arms from the lower valve, by which they are attached to stems of sea-weed, &c. Fig. 180, O. edulis. Fig. 181, O. folium. (Dendostrea, Sw.) Fig. 182, Gryphæa incurva. Fig. 183, Exogyra conica.OTIDES. Bl. The first order of Scutibranchiata, Bl. containing the genera Haliotis and Ancylus.OTION. Leach. (ωτιον, a little ear.)Order.Pedunculated Cirripedes, Lam.—Descr.Body sub-quadrate, supported on a fleshy pedicle with a gaping aperture and two posterior auricular tubes; valves five, separate, two semilunar, placed at the sides of the aperture, two terminal, very small, one dorsal, minute.—Obs.Otion differs from Cineras in having two cylindrical posterior tubes, and in the extreme minuteness of three out of five of the valves. Found on spars floating in the sea, &c. O. Cuvierii, (Lepas aurita, Linn.) Fig. 43, O. Cuvieri.OTIS. Humph.Auricula, Lam.OVATE. (Ovatus.) Egg-shaped or oval.OVEOLITHES. Montf. A microscopic shell resembling Bulla.OVIPAROUS MOLLUSCA. Those which produce their young in eggs. Used in distinction from theViviparous Mollusca, whose young are perfectly formed before they leave the body of the parent.OUTER LIP. SeeLabrum.OVULUM. Brug. (Ovum, an egg, dim.)Fam.Convoluta, Lam. Angyostomata, Bl.—Descr.Ovate or fusiform, smooth, convolute, spire covered; aperture narrow, with a canal at each extremity; outer lip crenulated, inflected; inner lip smooth, callous towards the spiral extremity; dorsal area wide, sometimes indistinctly marked.—Obs.The Ovula were placed by Linnæus in his genus Bulla, from which they are very remote. They differ from Cypræa in having the inner lip smooth. We have given representations of their different forms as follows: O. Ovum, fig. 442. O. verrucosum, (Calpurnus Montf.) fig. 441. O. Volva, the weaver's shuttle (Radius, Montf.) fig. 442. O. gibbosum, (Ultimus, Montf.) fig. 443.OXYSTOMATA. Bl. The fifth family of Asiphonibranchiata, Bl. This family appears to have been formed for the express purpose of providing a place in the system for the genus Janthina, which seems to bear so little analogy with other genera of Mollusca, that conchological writers have been puzzled to know where to place it.PACHYLABRA. Sw.Pachystoma, Guild. A sub-genus of Ampullaria, the outer lip of which is thickened within.Ex.Ampullaria globosa.PACHYMYA. Sow. (παχυς,pachus, thick, andMya.)Fam.Cardiacea? Lam.—Descr.Obliquely elongated, equivalve, thick, sub-bilobed, with beaks near the anterior extremity; ligament partly immersed attached to prominent fulcra.—Obs.This singular fossil is shaped like Modiola, but the shell being extremely thick, and the ligament attached to a prominent fulcrum, it is difficult to know where to place it. Fig. 130, Pachymya Gigas.PACHYSTOMA. Guild. (παχυς,pachus, thick;στομα,stoma, mouth.) A genus composed of such species of Ampullaria, Auct. as have the edge of the aperture thickened and grooved within so as to form a sort of ledge upon which the operculum rests. Ampullaria globosa and corrugata are examples of this variation. The name Pachylabra is given to such species by Swainson, who objects to the above name on account of its having been previously used to a genus of fishes. Fig. 539.PACHYTOMA. Sw. A sub-genus of Helicina, thus described, "Aperture entire; the inner lip very thick; the spiral whorls hardly convex; P. occidentalis. Zool. J. iii. 15. f. 6-10. viridis, Zool. Journ. i. pl. 6. f. 7." Sw. p. 337.PACLITES. Montf. A genus composed of species of Belemnites, Auct. described towards the extremity, with a pore, at the apex, and a straight lengthened aperture.Ex.B. ungulatus, Bl.PADOLLUS. Montf. A genus composed of species ofHaliotis, with a strongly marked spiral groove.Ex.H. tricostalis, Lam. Fig. 339.PAGODELLA. Sw. A sub-genus of Trochus, thus described: "Trochiform; generally thin, and always not pearlaceous; aperture and pillar perfectly united and entire; operculum horny. P. major. Mart. 163. f. 1541, 1542. tectum-persicum. Ib. f. 1543, 1544." Sw. p. 351.PALLEAL IMPRESSION. (Pallium, a mantle.) The mark or groove formed in a bivalve shell by the muscular attachment of the mantle, which, being always found near the margin of the shell, is sometimes termed the marginal impression. In bivalves with two muscular impressions it passes from one to the other. If in passing, it takes a bend inwards posteriorly, it is said to be sinuated, and that part is called by Mr. Gray, the Siphonal scar.PALLIOBRANCHIATA. Bl. The first order of the class Acephalophora. Bl. The animals of this order are described as more or less compressed, included between the two valves of a bivalve shell, one inferior, the other superior, joining at the back and opening in front. The Palliobranchiata in the system of De Blainville correspond with the Brachiopoda in the system of Lamarck, and the shells may be known by their being symmetrical. This order contains in the first section of symmetrical bivalves, Lingula, Terebratula, Thecidium, Strophomena, Plagiostoma, Dianchora and Podopsis: in the second section, Orbicula and Crania.PALMATED. Flattened like a palm, as the fronds or fringes of some Murices.PALMINA. Gray. Differing fromOtionin having but one auricle.PALUDINA. Lam.Fam.Peristomata, Lam. Cricostomata, Bl—Descr.Varying in form from oval to globose, in some instances oblong, covered with a greenish horny epidermis; spire acute, composed of rounded whorls; aperture ovate; peritreme entire, slightly modified by the last whorl; operculum horny, concentric. Europe, North America, East Indies, China, &c.—Obs.The construction of the operculum distinguishes this genus of freshwater shells from Valvata and Cyclostoma. The Paludinæ are viviparous. Fig. 321. P. Achatina.PALUDOMUS. Sw. A genus of the family of "Melanianæ," Sw. described as differing from Melania in having the spire shorter than the aperture. Sw. p. 340.PANDORA. Brug.Fam.Corbulacea, Lam. Pyloridea, Bl.—Descr.Thin, inequivalve, pearly within, rounded anteriorly, rostrated posteriorly; right valve flat with a cardinal tooth, or short rib, and a slit containing the cartilage with a narrow plate on the dorsal edge turned towards the left valve; left valve concave, with a receptacle for the cardinal tooth of the right valve and the internal cartilage; no external ligament. Europe, America, Ceylon, &c.—Obs.This well known genus is in no danger of being confounded with any other shell. Fig. 90. P. rostrata.PANOPÆA. Menard.Fam.Solenacea, Lam. Pyloridea, Bl.—Descr.Equivalve, inequilateral, oval, gaping at both extremities; hinge with an acute cardinal tooth in each valve, and a large callosity near the umbones supporting the ligament; muscular impressions two, distant, oval; palleal impression with a large sinus. Britain, North America, Mediterranean, Australia, &c.—Obs.This genus resembles Mya in general appearance, but differs in having an external ligament and a sharp tooth, instead of the broad spoon-shaped process in the hinge of the latter genus. Fig. 65. P. Australis.PAPER SAILOR. A common name given to the Argonauta.PAPILLARY. (Papilla, a teat.) Shaped like a teat. This term is applied by conchologists when the apex of the spire of an univalve shell is rounded like a teat and not spiral up to the extreme point; as the apex of Cymba, fig. 434.PAPYRACEOUS. (Papyrus, a kind of paper made of the flags of the river Nile in Egypt.) Of a thin, light texture, resembling that of paper. An example of this is to be seen in the Argonauta, commonly called the "Paper Sailor," fig. 485, and in the Pholas papyracea, fig. 56.PAPYRIDEA. Sw. A sub-genus of Cardium, thus described; "Shell heart-shaped, or transversely oval; inequilateral; the anterior side almost always gaping; representing the Pholidæ. P. Soleniforme, Wood, Conch. pl. 56. f. 3.—apertum, Ib. 56. f. 2.—transversum, Sow. Conch. f. 4.—ringens, Wood, pl. 53. f. 1, 2."PARACEPHALOPHORA. Bl. The second class of the type Malacozoa, Bl. divided into the sub-classes: P. dioica, P. monoica, P. hermaphrodita.PARIES. (A wall.) The principal part of a multivalve shell, forming a circular wall round the body of the animal, and composed of one or more valves which are called the parietal valves.PARIETAL VALVES. The principal valves of multivalve shells surrounding the body like a wall; as distinguished from the opercular valves, or those which compose the operculum.PARMACELLA. Cuv. (A little cell.)Fam.Limacinea, Lam. and Bl.—Descr.Haliotoid, internal, thin; spire flat, consisting of one or two rapidly increasing whorls; aperture as large as the whole shell, with the dorsal margins inflected.—Obs.This description applies to Parmacella of Cuvier. The shell figured in Sowerby's Genera under that name is Cryptella of Webb. Fig. 257, P. Olivieri. Fig. 258, P. Palliolum.PARMOPHORUS. Bl. A genus composed ofEmarginulaelongata, Auct. and other species of a similarly elongated form. Australian. Fig. 242. P. elongatus.PARTULA. Fer.Fam.Colimacea, Lam. Auriculacea, Fer.—Descr.Conical, smooth; spire equal to the aperture in length, consisting of few whorls; aperture auriform; outer lip reflected, broad; inner lip reflected, with a slight prominence on the columella. P. australis, fig. 302.PASITHÆA. Lea. A genus formed of some pyramidal shells, described as resembling Melania, but separated from that genus on account of being marine fossils. Fig. 317, P. striata.PATELLA. Auct. (A dishorplatter.)Fam.Phyllidiana, Lam. Retifera, Bl.—Descr.Symmetrical, compresso-conical, nearly regular, oblong or oval; apex sub-central, inclining towards the anterior margin; aperture oval, forming the base of the shell; internal surface smooth; with a muscular impression shaped like a horse-shoe, with the ends bending forwards, encircling and dividing the space all round, except where the interruption occurs to receive the head of the animal; external surface ribbed, grooved, striated or banded radiately. On rocks and sea-weeds in all climates.—Obs.Patelloida differs from Patella in the construction of the animal; Siphonaria, in the lateral siphon; and Ancylus, in the oblique twist of the axis, as well as in the nature of the animal. The Patellæ are marine. Fig. 229, P. Oculus.PATELLIFORM. (Patella, a dish;forma, shape.) Shaped like a dish, or like shells of the genus Patella.PATELLOIDA. Quoy and Gaimard.Lottia, Gray.—Fam.Phyllidiana, Lam.—Descr.Patelliform, rather flat; apex obtuse, leaning towards the posterior margin; muscular impression not symmetrical, but widest on the right side near the head of the animal; central disc of a variable brown colour. On rocks and sea-weeds in all climates.—Obs.The shells of this genus so closely resemble Patella that it is almost impossible to make the distinction from the shells alone. They are, however, generally flatter, and have the apex placed somewhat nearer the posterior margin. The animals are very distinct. Fig. 231, P. Antillarum.PATELLOIDEA, Bl. or patelliform shells. The third family of the order Monopleurobranchiata, Bl.; the animals of which are described as depressed, flattened, covered by a wide external shell, which is patelliform and non-symmetrical. This family contains the genera Umbrella and Siphonaria.PATROCLES. Montf. A genus of microscopic Foraminifera.PATULARIA. Sw. A sub-genus of "Anodontinæ," Sw. thus described: "Shell nearly equilateral, round or cordate; no teeth. P. ovata, Sw."Ex.Conch.pl. 36. rotundatus, Ib. pl. 137.PAVONIA. D'Orb. A genus of microscopic Foraminifera.PAXYODON. Schum.Hyria, Lam.PECTEN. Brug. (A comb.)Fam.Pectenides, Lam. Subostracea, Bl.—Descr.Inequivalve, ribbed longitudinally, nearly equilateral, with a triangular auricle on each side of the umbones; hinge linear, destitute of teeth, having a central pit containing the cartilage; muscular impressions one in each valve, large, sub-central.—Obs.This genus of beautiful shells, to which the well known Scallop belongs, contains numerous species, some of which are found in the British Seas. The Hinnites Pusio (P. Pusio of some authors) has been separated on account of the irregularity of the external surface of one valve. Fig. 171 to 173.PECTENIDES. Lam. A family belonging to the second section of the order Conchifera Dimyaria, Lam. including the following genera.
OSTRACEA. Bl. The first family of the order Lamellibranchiata, Bl. containing the genera Anomia, Placuna, Harpax, Ostrea (including Dendostrea, Sw.) Gryphæa. To these may be added Placunanomia, Brod. and Mulleria.
OSTREA. Auct. (οστρεον,ostreon, a bone.)Fam.Ostracea, Lam. and Bl.—Descr.Irregular, inequivalve, generally inequilateral, foliaceous, attached by part of the lower valve; hinge sometimes slightly crenated; destitute of teeth; with the ligament spread upon the lower part of a central, triangular area, which is divided into three parts; upper valve much flatter than the lower; muscular impressions one in each valve, large, sub-central, sub-orbicular, with one very minute.—Obs.The Linnæan Genus Ostrea includes the Pectens and many other genera so different from each other that, without any desire to increase the number of genera, it was found necessary by subsequent authors to separate them. The common Oyster is the type of this genus as at present constituted, and is well known to be abundant in various parts of the world. Those which depart furthest from this type are the Gryphæa, Lam. with a prominent, incurved umbo in the lower valve. The Dendostrea, Sw. with margins characterized by strongly angulated folds, throws out arms from the lower valve, by which they are attached to stems of sea-weed, &c. Fig. 180, O. edulis. Fig. 181, O. folium. (Dendostrea, Sw.) Fig. 182, Gryphæa incurva. Fig. 183, Exogyra conica.
OTIDES. Bl. The first order of Scutibranchiata, Bl. containing the genera Haliotis and Ancylus.
OTION. Leach. (ωτιον, a little ear.)Order.Pedunculated Cirripedes, Lam.—Descr.Body sub-quadrate, supported on a fleshy pedicle with a gaping aperture and two posterior auricular tubes; valves five, separate, two semilunar, placed at the sides of the aperture, two terminal, very small, one dorsal, minute.—Obs.Otion differs from Cineras in having two cylindrical posterior tubes, and in the extreme minuteness of three out of five of the valves. Found on spars floating in the sea, &c. O. Cuvierii, (Lepas aurita, Linn.) Fig. 43, O. Cuvieri.
OTIS. Humph.Auricula, Lam.
OVATE. (Ovatus.) Egg-shaped or oval.
OVEOLITHES. Montf. A microscopic shell resembling Bulla.
OVIPAROUS MOLLUSCA. Those which produce their young in eggs. Used in distinction from theViviparous Mollusca, whose young are perfectly formed before they leave the body of the parent.
OUTER LIP. SeeLabrum.
OVULUM. Brug. (Ovum, an egg, dim.)Fam.Convoluta, Lam. Angyostomata, Bl.—Descr.Ovate or fusiform, smooth, convolute, spire covered; aperture narrow, with a canal at each extremity; outer lip crenulated, inflected; inner lip smooth, callous towards the spiral extremity; dorsal area wide, sometimes indistinctly marked.—Obs.The Ovula were placed by Linnæus in his genus Bulla, from which they are very remote. They differ from Cypræa in having the inner lip smooth. We have given representations of their different forms as follows: O. Ovum, fig. 442. O. verrucosum, (Calpurnus Montf.) fig. 441. O. Volva, the weaver's shuttle (Radius, Montf.) fig. 442. O. gibbosum, (Ultimus, Montf.) fig. 443.
OXYSTOMATA. Bl. The fifth family of Asiphonibranchiata, Bl. This family appears to have been formed for the express purpose of providing a place in the system for the genus Janthina, which seems to bear so little analogy with other genera of Mollusca, that conchological writers have been puzzled to know where to place it.
PACHYLABRA. Sw.Pachystoma, Guild. A sub-genus of Ampullaria, the outer lip of which is thickened within.Ex.Ampullaria globosa.
PACHYMYA. Sow. (παχυς,pachus, thick, andMya.)Fam.Cardiacea? Lam.—Descr.Obliquely elongated, equivalve, thick, sub-bilobed, with beaks near the anterior extremity; ligament partly immersed attached to prominent fulcra.—Obs.This singular fossil is shaped like Modiola, but the shell being extremely thick, and the ligament attached to a prominent fulcrum, it is difficult to know where to place it. Fig. 130, Pachymya Gigas.
PACHYSTOMA. Guild. (παχυς,pachus, thick;στομα,stoma, mouth.) A genus composed of such species of Ampullaria, Auct. as have the edge of the aperture thickened and grooved within so as to form a sort of ledge upon which the operculum rests. Ampullaria globosa and corrugata are examples of this variation. The name Pachylabra is given to such species by Swainson, who objects to the above name on account of its having been previously used to a genus of fishes. Fig. 539.
PACHYTOMA. Sw. A sub-genus of Helicina, thus described, "Aperture entire; the inner lip very thick; the spiral whorls hardly convex; P. occidentalis. Zool. J. iii. 15. f. 6-10. viridis, Zool. Journ. i. pl. 6. f. 7." Sw. p. 337.
PACLITES. Montf. A genus composed of species of Belemnites, Auct. described towards the extremity, with a pore, at the apex, and a straight lengthened aperture.Ex.B. ungulatus, Bl.
PADOLLUS. Montf. A genus composed of species ofHaliotis, with a strongly marked spiral groove.Ex.H. tricostalis, Lam. Fig. 339.
PAGODELLA. Sw. A sub-genus of Trochus, thus described: "Trochiform; generally thin, and always not pearlaceous; aperture and pillar perfectly united and entire; operculum horny. P. major. Mart. 163. f. 1541, 1542. tectum-persicum. Ib. f. 1543, 1544." Sw. p. 351.
PALLEAL IMPRESSION. (Pallium, a mantle.) The mark or groove formed in a bivalve shell by the muscular attachment of the mantle, which, being always found near the margin of the shell, is sometimes termed the marginal impression. In bivalves with two muscular impressions it passes from one to the other. If in passing, it takes a bend inwards posteriorly, it is said to be sinuated, and that part is called by Mr. Gray, the Siphonal scar.
PALLIOBRANCHIATA. Bl. The first order of the class Acephalophora. Bl. The animals of this order are described as more or less compressed, included between the two valves of a bivalve shell, one inferior, the other superior, joining at the back and opening in front. The Palliobranchiata in the system of De Blainville correspond with the Brachiopoda in the system of Lamarck, and the shells may be known by their being symmetrical. This order contains in the first section of symmetrical bivalves, Lingula, Terebratula, Thecidium, Strophomena, Plagiostoma, Dianchora and Podopsis: in the second section, Orbicula and Crania.
PALMATED. Flattened like a palm, as the fronds or fringes of some Murices.
PALMINA. Gray. Differing fromOtionin having but one auricle.
PALUDINA. Lam.Fam.Peristomata, Lam. Cricostomata, Bl—Descr.Varying in form from oval to globose, in some instances oblong, covered with a greenish horny epidermis; spire acute, composed of rounded whorls; aperture ovate; peritreme entire, slightly modified by the last whorl; operculum horny, concentric. Europe, North America, East Indies, China, &c.—Obs.The construction of the operculum distinguishes this genus of freshwater shells from Valvata and Cyclostoma. The Paludinæ are viviparous. Fig. 321. P. Achatina.
PALUDOMUS. Sw. A genus of the family of "Melanianæ," Sw. described as differing from Melania in having the spire shorter than the aperture. Sw. p. 340.
PANDORA. Brug.Fam.Corbulacea, Lam. Pyloridea, Bl.—Descr.Thin, inequivalve, pearly within, rounded anteriorly, rostrated posteriorly; right valve flat with a cardinal tooth, or short rib, and a slit containing the cartilage with a narrow plate on the dorsal edge turned towards the left valve; left valve concave, with a receptacle for the cardinal tooth of the right valve and the internal cartilage; no external ligament. Europe, America, Ceylon, &c.—Obs.This well known genus is in no danger of being confounded with any other shell. Fig. 90. P. rostrata.
PANOPÆA. Menard.Fam.Solenacea, Lam. Pyloridea, Bl.—Descr.Equivalve, inequilateral, oval, gaping at both extremities; hinge with an acute cardinal tooth in each valve, and a large callosity near the umbones supporting the ligament; muscular impressions two, distant, oval; palleal impression with a large sinus. Britain, North America, Mediterranean, Australia, &c.—Obs.This genus resembles Mya in general appearance, but differs in having an external ligament and a sharp tooth, instead of the broad spoon-shaped process in the hinge of the latter genus. Fig. 65. P. Australis.
PAPER SAILOR. A common name given to the Argonauta.
PAPILLARY. (Papilla, a teat.) Shaped like a teat. This term is applied by conchologists when the apex of the spire of an univalve shell is rounded like a teat and not spiral up to the extreme point; as the apex of Cymba, fig. 434.
PAPYRACEOUS. (Papyrus, a kind of paper made of the flags of the river Nile in Egypt.) Of a thin, light texture, resembling that of paper. An example of this is to be seen in the Argonauta, commonly called the "Paper Sailor," fig. 485, and in the Pholas papyracea, fig. 56.
PAPYRIDEA. Sw. A sub-genus of Cardium, thus described; "Shell heart-shaped, or transversely oval; inequilateral; the anterior side almost always gaping; representing the Pholidæ. P. Soleniforme, Wood, Conch. pl. 56. f. 3.—apertum, Ib. 56. f. 2.—transversum, Sow. Conch. f. 4.—ringens, Wood, pl. 53. f. 1, 2."
PARACEPHALOPHORA. Bl. The second class of the type Malacozoa, Bl. divided into the sub-classes: P. dioica, P. monoica, P. hermaphrodita.
PARIES. (A wall.) The principal part of a multivalve shell, forming a circular wall round the body of the animal, and composed of one or more valves which are called the parietal valves.
PARIETAL VALVES. The principal valves of multivalve shells surrounding the body like a wall; as distinguished from the opercular valves, or those which compose the operculum.
PARMACELLA. Cuv. (A little cell.)Fam.Limacinea, Lam. and Bl.—Descr.Haliotoid, internal, thin; spire flat, consisting of one or two rapidly increasing whorls; aperture as large as the whole shell, with the dorsal margins inflected.—Obs.This description applies to Parmacella of Cuvier. The shell figured in Sowerby's Genera under that name is Cryptella of Webb. Fig. 257, P. Olivieri. Fig. 258, P. Palliolum.
PARMOPHORUS. Bl. A genus composed ofEmarginulaelongata, Auct. and other species of a similarly elongated form. Australian. Fig. 242. P. elongatus.
PARTULA. Fer.Fam.Colimacea, Lam. Auriculacea, Fer.—Descr.Conical, smooth; spire equal to the aperture in length, consisting of few whorls; aperture auriform; outer lip reflected, broad; inner lip reflected, with a slight prominence on the columella. P. australis, fig. 302.
PASITHÆA. Lea. A genus formed of some pyramidal shells, described as resembling Melania, but separated from that genus on account of being marine fossils. Fig. 317, P. striata.
PATELLA. Auct. (A dishorplatter.)Fam.Phyllidiana, Lam. Retifera, Bl.—Descr.Symmetrical, compresso-conical, nearly regular, oblong or oval; apex sub-central, inclining towards the anterior margin; aperture oval, forming the base of the shell; internal surface smooth; with a muscular impression shaped like a horse-shoe, with the ends bending forwards, encircling and dividing the space all round, except where the interruption occurs to receive the head of the animal; external surface ribbed, grooved, striated or banded radiately. On rocks and sea-weeds in all climates.—Obs.Patelloida differs from Patella in the construction of the animal; Siphonaria, in the lateral siphon; and Ancylus, in the oblique twist of the axis, as well as in the nature of the animal. The Patellæ are marine. Fig. 229, P. Oculus.
PATELLIFORM. (Patella, a dish;forma, shape.) Shaped like a dish, or like shells of the genus Patella.
PATELLOIDA. Quoy and Gaimard.Lottia, Gray.—Fam.Phyllidiana, Lam.—Descr.Patelliform, rather flat; apex obtuse, leaning towards the posterior margin; muscular impression not symmetrical, but widest on the right side near the head of the animal; central disc of a variable brown colour. On rocks and sea-weeds in all climates.—Obs.The shells of this genus so closely resemble Patella that it is almost impossible to make the distinction from the shells alone. They are, however, generally flatter, and have the apex placed somewhat nearer the posterior margin. The animals are very distinct. Fig. 231, P. Antillarum.
PATELLOIDEA, Bl. or patelliform shells. The third family of the order Monopleurobranchiata, Bl.; the animals of which are described as depressed, flattened, covered by a wide external shell, which is patelliform and non-symmetrical. This family contains the genera Umbrella and Siphonaria.
PATROCLES. Montf. A genus of microscopic Foraminifera.
PATULARIA. Sw. A sub-genus of "Anodontinæ," Sw. thus described: "Shell nearly equilateral, round or cordate; no teeth. P. ovata, Sw."Ex.Conch.pl. 36. rotundatus, Ib. pl. 137.
PAVONIA. D'Orb. A genus of microscopic Foraminifera.
PAXYODON. Schum.Hyria, Lam.
PECTEN. Brug. (A comb.)Fam.Pectenides, Lam. Subostracea, Bl.—Descr.Inequivalve, ribbed longitudinally, nearly equilateral, with a triangular auricle on each side of the umbones; hinge linear, destitute of teeth, having a central pit containing the cartilage; muscular impressions one in each valve, large, sub-central.—Obs.This genus of beautiful shells, to which the well known Scallop belongs, contains numerous species, some of which are found in the British Seas. The Hinnites Pusio (P. Pusio of some authors) has been separated on account of the irregularity of the external surface of one valve. Fig. 171 to 173.
PECTENIDES. Lam. A family belonging to the second section of the order Conchifera Dimyaria, Lam. including the following genera.
1.Pecten.Unattached, includingDecatopectenandHinnites. Fig. 171, 172, 173.2.Lima.Unattached, gaping, Fig. 174.3.Plagiostoma.Unattached, with an area between the umbones. Fig. 176.4.Dianchora.Attached by the point of the umbo. Fig. 175.5.Spondylus.Attached, irregular, a triangular area in one valve, divided by a slit. Fig. 177.6.Plicatula.Plicated, a very small area in one valve. Fig. 178.
1.Pecten.Unattached, includingDecatopectenandHinnites. Fig. 171, 172, 173.
2.Lima.Unattached, gaping, Fig. 174.
3.Plagiostoma.Unattached, with an area between the umbones. Fig. 176.
4.Dianchora.Attached by the point of the umbo. Fig. 175.
5.Spondylus.Attached, irregular, a triangular area in one valve, divided by a slit. Fig. 177.
6.Plicatula.Plicated, a very small area in one valve. Fig. 178.
PECTINATED. (Pecten, a comb.) Marked in a regular series of ridges.PECTUNCULUS. (Pecten, dim.)Fam.Arcacea, Lam. and Bl.—Descr.Equivalve, sub-equilateral, orbicular, thick, covered with a velvety epidermis, striated longitudinally; ventral margin denticulated within; hinge semi-circular, with a series of small teeth on each side of the umbones, which are separated by a small triangular disc in each valve bearing the ligament; muscular impressions two in each valve, strongly marked, united by an entire palleal impression.—Obs.Linnæan conchologists have mixed this genus with Arca, from which it is, however, totally distinct, not only in the roundness of the general form, but also, and principally, in the curve of the hinge line; in fact the characters of this genus are so strongly marked that there is no danger of confounding it with any other. It does not contain many species; two or three are British. The fossil species occur in London Clay and Calcaire-grossiér. Fig. 134, P. pilosus.PEDICLE or PEDUNCLE. (Pedunculus, a little foot.) The stem or organ of attachment of the class of shells called in the system of Lamarck "Pedunculated Cirripedes," consisting of a fleshy tendinous tube, by the lower end of which they are attached to sub-marine substances.PEDICULARIA. Sw. A genus of "Scutibranchia," thus described: "Shell irregular, sub-patelliform; a thick, large, obsolete apex on one of the longest sides, and an internal callous rim within, on one side only; circumference undulated, irregular. P. Sicula, Sw." Sw. p. 357. Sicily. A singular shell of the nature of Calyptræa, which is found attached to corals, conforming its shape to the irregularity of their surface, and fitting closely.Ex.Fig. 513.PEDIPES. Adanson.Fam.Auriculacea, Bl. Colimacea, Lam.—Descr.Sub-globose, longitudinal, thick, striated; spire equal to the aperture in length; aperture sub-ovate; peritreme sharp, thickened within, modified by the last whorl; columella with three strong plaits on the inner edge; outer lip with one fold.—Obs.This genus contains but one or two small recent species, which in some respects resemble Auricula, from which it is known by the thickness of its shell, and its globular form. Fig. 299, P. Adansoni. Coast of Africa.PEDUM. Lam. (A shepherd's crook.)Fam.Pectinides, Lam. Sub-ostracea, Bl.—Descr.Irregular, inequivalve, sub-equilateral, attached by a byssus passing through a sinus in the lower valve; hinge toothless, with a triangular area in each valve, separating the umbones; ligament contained in a groove running across the area; muscular impressions one in each valve, large, sub-orbicular; both valves flat, narrow at the dorsal, broad at the ventral extremities; lower valve with raised edges overwrapping the upper.—Obs.This singular genus, of which only one species is known, differs from Ostrea, not only in shape and structure, but also in the mode of attachment, which is by means of a byssus passing through the lower valve, in Pedum, but by a portion of the outer surface of the shell in Ostrea. P. Spondyloideum (fig. 179) is the only species at present known. Moluccas.PEDUNCLE. SeePedicle.PEDUNCULATED. (Pedunculus, a little foot.) Attached to external objects by a hollow fleshy tube, called the Peduncle.PEDUNCULATED CIRRIPEDES. Lam. An order consisting of molluscs which have multivalve shells, supported on a peduncle. The genera which it contains are thus distinguished:
PECTINATED. (Pecten, a comb.) Marked in a regular series of ridges.
PECTUNCULUS. (Pecten, dim.)Fam.Arcacea, Lam. and Bl.—Descr.Equivalve, sub-equilateral, orbicular, thick, covered with a velvety epidermis, striated longitudinally; ventral margin denticulated within; hinge semi-circular, with a series of small teeth on each side of the umbones, which are separated by a small triangular disc in each valve bearing the ligament; muscular impressions two in each valve, strongly marked, united by an entire palleal impression.—Obs.Linnæan conchologists have mixed this genus with Arca, from which it is, however, totally distinct, not only in the roundness of the general form, but also, and principally, in the curve of the hinge line; in fact the characters of this genus are so strongly marked that there is no danger of confounding it with any other. It does not contain many species; two or three are British. The fossil species occur in London Clay and Calcaire-grossiér. Fig. 134, P. pilosus.
PEDICLE or PEDUNCLE. (Pedunculus, a little foot.) The stem or organ of attachment of the class of shells called in the system of Lamarck "Pedunculated Cirripedes," consisting of a fleshy tendinous tube, by the lower end of which they are attached to sub-marine substances.
PEDICULARIA. Sw. A genus of "Scutibranchia," thus described: "Shell irregular, sub-patelliform; a thick, large, obsolete apex on one of the longest sides, and an internal callous rim within, on one side only; circumference undulated, irregular. P. Sicula, Sw." Sw. p. 357. Sicily. A singular shell of the nature of Calyptræa, which is found attached to corals, conforming its shape to the irregularity of their surface, and fitting closely.Ex.Fig. 513.
PEDIPES. Adanson.Fam.Auriculacea, Bl. Colimacea, Lam.—Descr.Sub-globose, longitudinal, thick, striated; spire equal to the aperture in length; aperture sub-ovate; peritreme sharp, thickened within, modified by the last whorl; columella with three strong plaits on the inner edge; outer lip with one fold.—Obs.This genus contains but one or two small recent species, which in some respects resemble Auricula, from which it is known by the thickness of its shell, and its globular form. Fig. 299, P. Adansoni. Coast of Africa.
PEDUM. Lam. (A shepherd's crook.)Fam.Pectinides, Lam. Sub-ostracea, Bl.—Descr.Irregular, inequivalve, sub-equilateral, attached by a byssus passing through a sinus in the lower valve; hinge toothless, with a triangular area in each valve, separating the umbones; ligament contained in a groove running across the area; muscular impressions one in each valve, large, sub-orbicular; both valves flat, narrow at the dorsal, broad at the ventral extremities; lower valve with raised edges overwrapping the upper.—Obs.This singular genus, of which only one species is known, differs from Ostrea, not only in shape and structure, but also in the mode of attachment, which is by means of a byssus passing through the lower valve, in Pedum, but by a portion of the outer surface of the shell in Ostrea. P. Spondyloideum (fig. 179) is the only species at present known. Moluccas.
PEDUNCLE. SeePedicle.
PEDUNCULATED. (Pedunculus, a little foot.) Attached to external objects by a hollow fleshy tube, called the Peduncle.
PEDUNCULATED CIRRIPEDES. Lam. An order consisting of molluscs which have multivalve shells, supported on a peduncle. The genera which it contains are thus distinguished:
1.Pentelasmis.Five valves. Fig. 34.2.Cineras.Five very minute valves distant from each other. Fig. 42.3.Otion.The same, but the animal has two auricles. Fig. 43. The genus Palmina, Gray, has but one.4.Octolasmis.Shaped like Pentelasmis, but with 7 or 8 valves. Fig. 41.5.Lithotrya.Five valves, peduncle scaly with a plate at the base. Fig. 39.6.Scalpellum.Shape square, valves 13, peduncle scaly. Fig. 35.7.Smilium.Same, but the peduncle hairy. Fig. 36.8.Ibla.Four valves, one pair long, one pair short, peduncle hairy. Fig. 40.9.Brismeus.Seven valves, even at the base. Fig. 38.10.Pollicipes.Principal valves in pairs, with many smaller valves at the base. This genus has been divided intoPollicipes, andCapitellum, the latter of which is founded upon Pollicipes Mitellus, Auct. Fig. 37 and 37*.
1.Pentelasmis.Five valves. Fig. 34.
2.Cineras.Five very minute valves distant from each other. Fig. 42.
3.Otion.The same, but the animal has two auricles. Fig. 43. The genus Palmina, Gray, has but one.
4.Octolasmis.Shaped like Pentelasmis, but with 7 or 8 valves. Fig. 41.
5.Lithotrya.Five valves, peduncle scaly with a plate at the base. Fig. 39.
6.Scalpellum.Shape square, valves 13, peduncle scaly. Fig. 35.
7.Smilium.Same, but the peduncle hairy. Fig. 36.
8.Ibla.Four valves, one pair long, one pair short, peduncle hairy. Fig. 40.
9.Brismeus.Seven valves, even at the base. Fig. 38.
10.Pollicipes.Principal valves in pairs, with many smaller valves at the base. This genus has been divided intoPollicipes, andCapitellum, the latter of which is founded upon Pollicipes Mitellus, Auct. Fig. 37 and 37*.
PELAGUS. Montf. A genus composed of species ofAmmonites, which have the spire covered by the last whorl, as in Nautilus and have an umbilicus.Orbulites. Bl.PELLUCID. Transparent.PELORUS. Montf.Polystomella, Bl. A genus of microscopic Foraminifera.PELORONTA. Oken.NeritaPeloronta, Auct. Fig. 330.PENEROPLIS. Montf. A genus of microscopic Foraminifera.PENICILLUS. Brug.Aspergillum, Auct.PENTALEPAS. Bl.Pentelasmis, Auct.PENTAMERUS. Sow. (Πεντε,pente, five;μερος,meros, part.)Fam.Brachiopoda, Lam.—Descr.Equilateral, inequivalve; one valve divided by a central septum into two parts; the other by two septa, into three parts; umbones incurved, imperforate.—Obs.Dalman remarks upon his genus Gypidia, that it is most probably identical withPentamerus, Sow. but rejects the name for two reasons; 1st. That it has already been applied to a class of insects; 2nd. He disputes the fact of the shell being quinquelocular, i.e. not counting the triangular foramen in the hinge of the larger valve as one of the divisions. Fig. 212, 213.PENTELASMIS. Leach. (πεντε,pente, five;ελασμα,elasma, plate.)Order.Pedunculated Cirripedes, Lam.—Descr.Compressed, conical, composed of five valves; lower lateral pair sub-trigonal; upper lateral pair elongated, sub-quadrate; dorsal valve arcuate, peduncle elongated, smooth. Found on floating wood in the sea.—Obs.This genus is known from all others of the order by the number of valves. Pentelasmis is the genus Anatifera of Lamarck. Lepas anatifer, Linn. Fossil species of this marine genus are found in the Calcaire-grossièr of Paris, and in other similar beds. Fig. 34, P. lævis.PENULTIMATE WHORL. The last whorl but one.PERA. Leach. A genus composed ofCyclasamnica, and other similar species.PERDIX. Montf.DoliumPerdix, Auct.PERFORATED. (Perforatus.) Bored through, as the apex of Fissurella, fig. 245, and Dentalium, fig. 2.PERFORATION. (Perforo, to bore, or pierce.) A round opening, having the appearance of being bored, as in Haliotis, fig. 338. Sometimes the term is applied to an umbilicus which penetrates a shell through the axis to the apex, as Eulima splendidula, fig. 348.PERIBOLUS. Brug. A genus founded upon young specimens ofCypræa, with their outer lips not formed.PERIOSTRACUM. A name used by Mr. Gray to signify the substance which covers the outer surface of many shells, called theEpidermisby most conchological writers. "Drap Marin" is the name given to this substance by French Naturalists.PERIPLOMA. Schum.Fam.Myariæ. A genus thus described: "Shell very thin with the left valve more ventricose than the right; hinge toothless, ligament double, the external portion thin, the internal part thick, placed upon prominent, sometimes spoon-shaped hinge laminæ, and supported by a transverse bone; muscular impressions two, distant, palleal impression sinuated posteriorly."Ex.P. inæquivalvis. fig. 72.Genus, Osteodesma, Deshayes.PERISTOMATA. Lam. A family belonging to the first section of the order Trachelipoda, containing the following genera:—
PELAGUS. Montf. A genus composed of species ofAmmonites, which have the spire covered by the last whorl, as in Nautilus and have an umbilicus.Orbulites. Bl.
PELLUCID. Transparent.
PELORUS. Montf.Polystomella, Bl. A genus of microscopic Foraminifera.
PELORONTA. Oken.NeritaPeloronta, Auct. Fig. 330.
PENEROPLIS. Montf. A genus of microscopic Foraminifera.
PENICILLUS. Brug.Aspergillum, Auct.
PENTALEPAS. Bl.Pentelasmis, Auct.
PENTAMERUS. Sow. (Πεντε,pente, five;μερος,meros, part.)Fam.Brachiopoda, Lam.—Descr.Equilateral, inequivalve; one valve divided by a central septum into two parts; the other by two septa, into three parts; umbones incurved, imperforate.—Obs.Dalman remarks upon his genus Gypidia, that it is most probably identical withPentamerus, Sow. but rejects the name for two reasons; 1st. That it has already been applied to a class of insects; 2nd. He disputes the fact of the shell being quinquelocular, i.e. not counting the triangular foramen in the hinge of the larger valve as one of the divisions. Fig. 212, 213.
PENTELASMIS. Leach. (πεντε,pente, five;ελασμα,elasma, plate.)Order.Pedunculated Cirripedes, Lam.—Descr.Compressed, conical, composed of five valves; lower lateral pair sub-trigonal; upper lateral pair elongated, sub-quadrate; dorsal valve arcuate, peduncle elongated, smooth. Found on floating wood in the sea.—Obs.This genus is known from all others of the order by the number of valves. Pentelasmis is the genus Anatifera of Lamarck. Lepas anatifer, Linn. Fossil species of this marine genus are found in the Calcaire-grossièr of Paris, and in other similar beds. Fig. 34, P. lævis.
PENULTIMATE WHORL. The last whorl but one.
PERA. Leach. A genus composed ofCyclasamnica, and other similar species.
PERDIX. Montf.DoliumPerdix, Auct.
PERFORATED. (Perforatus.) Bored through, as the apex of Fissurella, fig. 245, and Dentalium, fig. 2.
PERFORATION. (Perforo, to bore, or pierce.) A round opening, having the appearance of being bored, as in Haliotis, fig. 338. Sometimes the term is applied to an umbilicus which penetrates a shell through the axis to the apex, as Eulima splendidula, fig. 348.
PERIBOLUS. Brug. A genus founded upon young specimens ofCypræa, with their outer lips not formed.
PERIOSTRACUM. A name used by Mr. Gray to signify the substance which covers the outer surface of many shells, called theEpidermisby most conchological writers. "Drap Marin" is the name given to this substance by French Naturalists.
PERIPLOMA. Schum.Fam.Myariæ. A genus thus described: "Shell very thin with the left valve more ventricose than the right; hinge toothless, ligament double, the external portion thin, the internal part thick, placed upon prominent, sometimes spoon-shaped hinge laminæ, and supported by a transverse bone; muscular impressions two, distant, palleal impression sinuated posteriorly."Ex.P. inæquivalvis. fig. 72.Genus, Osteodesma, Deshayes.
PERISTOMATA. Lam. A family belonging to the first section of the order Trachelipoda, containing the following genera:—
1.Ampullaria.Globose or discoidal; operculum concentric; includingPachystoma,Lanistes,Ceratodes. Fig. 318 to 320.2.Paludina.Oval; operculum concentric. Fig. 321.3.Valvata.Globose; operculum spiral. Fig. 322.
1.Ampullaria.Globose or discoidal; operculum concentric; includingPachystoma,Lanistes,Ceratodes. Fig. 318 to 320.
2.Paludina.Oval; operculum concentric. Fig. 321.
3.Valvata.Globose; operculum spiral. Fig. 322.
PERISTOME. The edge of the aperture, including the inner and outer lips.PERITREME. A term used to express the whole circumference of the aperture of a spiral shell. It is said to be notched or entire, simple, reflected, round or oval, &c.PERLAMATER. Schum. (Mother of Pearl.)MeleagrinaMargaritifera, Lam. The pearl oyster.PERNA. Auct. ("Pernæ concharum generis," Plin.)Fam.Malleacea, Lam.—Descr.Sub-equivalve, irregular, compressed, foliaceous; hinge straight, linear, composed of a series of transverse, parallel grooves, containing the cartilage and intermediate spaces bearing the ligament; anterior margin with a sinus for the passage of a byssus; posterior ventral margin oblique, attenuated.Obs.This genus is known from Crenatula by the straightness, number and regularity of the grooves in the hinge and the sinus, for the passage of the byssus. Fig. 166, P. Ephippium. Mostly tropical.PERSICULA. Schum. A genus formed ofMarginellaPersicula, Auct. and other species having the spire concealed. Fig. 438.PERSONA. Montf. (Mask). A genus composed ofTritonAnus, Auct. and similar species. Fig. 401.PETRICOLA. Lam. (Petrus, a stone;cola, an inhabitant.)Fam.Lithophagidæ, Lam.—Descr.Equivalve, inequilateral, transversely ovate or oblong, rather irregular, anterior side rounded; posterior side more or less attenuated, slightly gaping; hinge with two cardinal teeth in each valve; muscular impressions two in each valve; palleal impression entire; ligament external.—Obs.The Petricolæ are found in holes made by the animals in rocks, madrepores, &c. They may be known from Saxicava by the regularity of their form and the teeth on the hinge. Fig. 91, 92.PETRIFIED FINGERS, CANDLES, SPECTRE CANDLES, &c. are vulgar terms by which fossils of the genus Belemnites were formerly known.PHAKELLOPLEURA. Guild. A genus composed of those species ofChiton, Auct. which have bunches of hairs or hyaline bristles on each side of each valve on the margin. The Chiton fascicularis, found on our own coasts, is a well known example. Fig. 506.PHARAMUS. Montf.Lenticulina, Bl. A genus of microscopic Foraminifera.PHARETRIUM. König. (φαρετρεων,pharetrion, a quiver.)—Descr.A testaceous body composed of two conical sheaths, one within the other, perforated at the apex, and joined together near the oral margin. P. fragile, fig. 3. In describing this genus, which appears to be the same asEntalisof Defrance, Mr. König expresses the supposition that it may probably belong to the class Pteropoda.PHASIANELLA. Auct. (Phasianus, a pheasant.)Fam.Turbinacea, Lam. Ellipsostomata, Bl.—Descr.Smooth, oval, variegated; aperture entire, oval; outer-lip thin; inner-lip thin, spread over a portion of the body whorl; columella smooth, rather thickened towards the base; operculum horny, spiral within; testaceous, incrassated without. Britain, Mediterranean, &c.; the fine large species are Australian. Some fossil species are found in the tertiary beds.—Obs.The shells composing this genus are richly marked with lines and waves of various and delicate colours, and if the genus be restricted to those species which are smooth, and which have a thick shelly operculum, we may regard it as well defined; but there are some spirally-grooved species ofTurbo, Linn. which, from their oval shape, have been considered as belonging to this genus. Such species should not, in our opinion, be retained in this genus; they belong to Littorina. P. variegata, fig. 367.PHITIA. Gray.Carychium, Müller.PHOLADARIA. Lam. A family of the order Conchifera Dimyaria, Lam. The animals contained in this family live in cavities bored by themselves in rocks, wood, &c. They are cylindrical in form. Lamarck here placesPholasandGastrochæna, the last of which belongs more properly to the family of Tubicolaria, where we have enumerated it. Pholas has been divided intoPholas, fig. 55,Martesia, which has the valves nearly closed; and Pholadidæa, fig. 56, which has the cup-shaped extension. The genus Pholadomya, fig. 67, has been added, although of doubtful character. The genus Galeomma, fig. 58, 59, has also been recently added.PHOLADIDÆA. Leach.Pholaspapyracea, Auct. Remarkable for the cup-shaped process at the posterior extremity. Fig. 56.PHOLADOMYA. Sow. (PholasandMya.)Fam.Pholadaria, Lam.—Descr.Thin, rather hyaline, equivalve, inequilateral, ventricose, posteriorly gaping, elongated, anteriorly short, rounding; ventral margin rather gaping; hinge with an elongated pit, and lateral plate in each valve; ligament external, short, muscular impressions two in each valve, rather indistinct; palleal impression with a large sinus.—Obs.The only recent species of this genus is from the island of Tortola. Several fossil species occur in rocks of the Oolitic series. Fig. 57, P. candida.PHOLAS. Auct. (Φωλεω,pholeo, to lie hid in a cavity.)Fam.Pholadaria, Lam.Adesmacea, Bl.—Descr.Transverse, oblong, equivalve, inequilateral, imbricated, gaping on both sides, the anterior hiatus being generally the largest, although sometimes nearly closed, with the dorsal margin surmounted with one or more laminar accessary valves; hinge callous, reflected, with a long curved tooth protruding from beneath the umbones in each valve.—Obs.This genus of marine shells, dwelling in holes formed in rocks, wood, &c. is easily distinguished from any other nearly allied genus by the curved, prominent, rib-like teeth. Fig. 55, P. Dactylus; 56. P. papyracea.PHOLEOBIUS. Leach. Part of the genusSaxicava, Auct.PHONEMUS. Montf. A genus of microscopic Foraminifera.PHORUS. Montf.Trochusagglutinans, Auct. Remarkable for the adhesion of little pebbles, dead shells, &c. to the outer edge of the whorls, which are taken up in the course of the growth of the shell. From this circumstance they are called "Collectors, Carriers, &c." Fig. 360. Recent species are brought from the East and West Indies; fossil species are found in the Tertiary beds.PHOS. Montf.Fam.Purpurifera? Lam.—Descr.Turrited, thick, cancellated, varicose; spire pointed, generally longer than the aperture; aperture rounded or oval; outer lip having internal ridges, with a sinus near the anterior termination; columella with an oblique fold; canal short, forming externally a raised varix.—Obs.The raised external surface of the canal, brings this genus near to Buccinum, while, in general appearance, most of the species more nearly resemble Murex. They have, however, no true varices on the whorls, but merely raised bars. Fig. 416, P. senticosus.PHYLLIDIANA. Lam. A family belonging to the first section of the order Gasteropoda, Lam. The genera belonging to this family may be distinguished as follows:
PERISTOME. The edge of the aperture, including the inner and outer lips.
PERITREME. A term used to express the whole circumference of the aperture of a spiral shell. It is said to be notched or entire, simple, reflected, round or oval, &c.
PERLAMATER. Schum. (Mother of Pearl.)MeleagrinaMargaritifera, Lam. The pearl oyster.
PERNA. Auct. ("Pernæ concharum generis," Plin.)Fam.Malleacea, Lam.—Descr.Sub-equivalve, irregular, compressed, foliaceous; hinge straight, linear, composed of a series of transverse, parallel grooves, containing the cartilage and intermediate spaces bearing the ligament; anterior margin with a sinus for the passage of a byssus; posterior ventral margin oblique, attenuated.Obs.This genus is known from Crenatula by the straightness, number and regularity of the grooves in the hinge and the sinus, for the passage of the byssus. Fig. 166, P. Ephippium. Mostly tropical.
PERSICULA. Schum. A genus formed ofMarginellaPersicula, Auct. and other species having the spire concealed. Fig. 438.
PERSONA. Montf. (Mask). A genus composed ofTritonAnus, Auct. and similar species. Fig. 401.
PETRICOLA. Lam. (Petrus, a stone;cola, an inhabitant.)Fam.Lithophagidæ, Lam.—Descr.Equivalve, inequilateral, transversely ovate or oblong, rather irregular, anterior side rounded; posterior side more or less attenuated, slightly gaping; hinge with two cardinal teeth in each valve; muscular impressions two in each valve; palleal impression entire; ligament external.—Obs.The Petricolæ are found in holes made by the animals in rocks, madrepores, &c. They may be known from Saxicava by the regularity of their form and the teeth on the hinge. Fig. 91, 92.
PETRIFIED FINGERS, CANDLES, SPECTRE CANDLES, &c. are vulgar terms by which fossils of the genus Belemnites were formerly known.
PHAKELLOPLEURA. Guild. A genus composed of those species ofChiton, Auct. which have bunches of hairs or hyaline bristles on each side of each valve on the margin. The Chiton fascicularis, found on our own coasts, is a well known example. Fig. 506.
PHARAMUS. Montf.Lenticulina, Bl. A genus of microscopic Foraminifera.
PHARETRIUM. König. (φαρετρεων,pharetrion, a quiver.)—Descr.A testaceous body composed of two conical sheaths, one within the other, perforated at the apex, and joined together near the oral margin. P. fragile, fig. 3. In describing this genus, which appears to be the same asEntalisof Defrance, Mr. König expresses the supposition that it may probably belong to the class Pteropoda.
PHASIANELLA. Auct. (Phasianus, a pheasant.)Fam.Turbinacea, Lam. Ellipsostomata, Bl.—Descr.Smooth, oval, variegated; aperture entire, oval; outer-lip thin; inner-lip thin, spread over a portion of the body whorl; columella smooth, rather thickened towards the base; operculum horny, spiral within; testaceous, incrassated without. Britain, Mediterranean, &c.; the fine large species are Australian. Some fossil species are found in the tertiary beds.—Obs.The shells composing this genus are richly marked with lines and waves of various and delicate colours, and if the genus be restricted to those species which are smooth, and which have a thick shelly operculum, we may regard it as well defined; but there are some spirally-grooved species ofTurbo, Linn. which, from their oval shape, have been considered as belonging to this genus. Such species should not, in our opinion, be retained in this genus; they belong to Littorina. P. variegata, fig. 367.
PHITIA. Gray.Carychium, Müller.
PHOLADARIA. Lam. A family of the order Conchifera Dimyaria, Lam. The animals contained in this family live in cavities bored by themselves in rocks, wood, &c. They are cylindrical in form. Lamarck here placesPholasandGastrochæna, the last of which belongs more properly to the family of Tubicolaria, where we have enumerated it. Pholas has been divided intoPholas, fig. 55,Martesia, which has the valves nearly closed; and Pholadidæa, fig. 56, which has the cup-shaped extension. The genus Pholadomya, fig. 67, has been added, although of doubtful character. The genus Galeomma, fig. 58, 59, has also been recently added.
PHOLADIDÆA. Leach.Pholaspapyracea, Auct. Remarkable for the cup-shaped process at the posterior extremity. Fig. 56.
PHOLADOMYA. Sow. (PholasandMya.)Fam.Pholadaria, Lam.—Descr.Thin, rather hyaline, equivalve, inequilateral, ventricose, posteriorly gaping, elongated, anteriorly short, rounding; ventral margin rather gaping; hinge with an elongated pit, and lateral plate in each valve; ligament external, short, muscular impressions two in each valve, rather indistinct; palleal impression with a large sinus.—Obs.The only recent species of this genus is from the island of Tortola. Several fossil species occur in rocks of the Oolitic series. Fig. 57, P. candida.
PHOLAS. Auct. (Φωλεω,pholeo, to lie hid in a cavity.)Fam.Pholadaria, Lam.Adesmacea, Bl.—Descr.Transverse, oblong, equivalve, inequilateral, imbricated, gaping on both sides, the anterior hiatus being generally the largest, although sometimes nearly closed, with the dorsal margin surmounted with one or more laminar accessary valves; hinge callous, reflected, with a long curved tooth protruding from beneath the umbones in each valve.—Obs.This genus of marine shells, dwelling in holes formed in rocks, wood, &c. is easily distinguished from any other nearly allied genus by the curved, prominent, rib-like teeth. Fig. 55, P. Dactylus; 56. P. papyracea.
PHOLEOBIUS. Leach. Part of the genusSaxicava, Auct.
PHONEMUS. Montf. A genus of microscopic Foraminifera.
PHORUS. Montf.Trochusagglutinans, Auct. Remarkable for the adhesion of little pebbles, dead shells, &c. to the outer edge of the whorls, which are taken up in the course of the growth of the shell. From this circumstance they are called "Collectors, Carriers, &c." Fig. 360. Recent species are brought from the East and West Indies; fossil species are found in the Tertiary beds.
PHOS. Montf.Fam.Purpurifera? Lam.—Descr.Turrited, thick, cancellated, varicose; spire pointed, generally longer than the aperture; aperture rounded or oval; outer lip having internal ridges, with a sinus near the anterior termination; columella with an oblique fold; canal short, forming externally a raised varix.—Obs.The raised external surface of the canal, brings this genus near to Buccinum, while, in general appearance, most of the species more nearly resemble Murex. They have, however, no true varices on the whorls, but merely raised bars. Fig. 416, P. senticosus.
PHYLLIDIANA. Lam. A family belonging to the first section of the order Gasteropoda, Lam. The genera belonging to this family may be distinguished as follows:
1.Chiton.Composed of eight valves; valves contingent. Fig. 227.2.Chitonellus.The same, with the valves distant. Fig. 228.3.Patella.Conical, symmetrical. Fig. 229, 230.4.Patelloida.Differing from Patella in the animal. Fig. 231.5.Siphonaria.With a siphon on one side. Fig. 231*.6.Scutella.Siphon close to the side of the head. Fig. 510, 511.
1.Chiton.Composed of eight valves; valves contingent. Fig. 227.
2.Chitonellus.The same, with the valves distant. Fig. 228.
3.Patella.Conical, symmetrical. Fig. 229, 230.
4.Patelloida.Differing from Patella in the animal. Fig. 231.
5.Siphonaria.With a siphon on one side. Fig. 231*.
6.Scutella.Siphon close to the side of the head. Fig. 510, 511.
PHYLLONOTUS. Sw. A sub-genus of Murex, thus described: "Canal moderate; varices foliated, laciniated, compressed, or resembling leaves; inflatus. Mart. 102. fig. 980, eurystoma. Zool. Ill. ii. 100. imperialis. Ib. pl. 109." Sw. p. 296.PHYSA. Drap. A genus formed for reversed species of Limnæa, Auct. Fig. 310, P. castanea.PHYSETER. Humph.Solarium, Lam.PILEOLUS. Cookson. (A little cap.)Fam.Neritacea, Lam.—Descr.Patelliform, with the apex sub-central, straight. In the lower disc, or under surface, the centre of which is rather raised or cushion-shaped, is placed the lateral, narrow, semilunar aperture, with the outer lip marginated and the inner lip crenulated.—Obs.This interesting genus is known only in a fossil state. Two species are found in the upper layer of Oolite, above the Bradford clay. The spire, although internal, connects this genus in some degree with Neritina. Still there is no danger of confounding them. Fig. 332, P. plicatus.PILEOPSIS. Lam.Capulus, Montf.PILLAR. The usual English name for the column which forms the axis of spiral shells, around which the whorls revolve. SeeColumella.PINNA. Auct. (The fin of a fish.)Fam.Mytilacea, Lam.—Descr.Equivalve, inequilateral, oblique, wedge-shaped, thin, horny; umbones terminal; hinge rectilinear, without teeth; anterior margin sinuated, to admit the passage of a byssus; posterior margin truncated, gaping; muscular impressions two in each valve; posterior large, sub-central; anterior small, terminal, sometimes double.—Obs.The beautiful large shells of which this genus is composed, are possessed of a large, flowing, silky byssus, of which gloves and hose have been manufactured. They have received their name from their resemblance to the pectoral fins of some fishes. Some species attain very large dimensions, and measure two feet in length. A very improbable story is told with regard to animals of this genus, namely that a certain small species of crab is in the habit of taking refuge from its enemies in the shell of the Pinna, into which it is received with great hospitality and kindness by the "blind slug," which inhabits it. In return for which kindness, he occasionally goes abroad to procure food for both. On his return he knocks at the shell, which is opened to receive him, and they share the supplies together in convivial security! Some species are smooth, although the greater number are imbricated or crisped outside. P. saccata, fig. 162.PINNATED. (FromPinna, a fin.) When a part of a shell is spread out and smooth, as in Rostellaria columbaria, fig. 403, it is said to bealated, or winged, but when the part which is spread is radiated or ribbed, like the fin of a fish, it ispinnated, as in Murex pinnatus, and Murex tripterus. (Conch. Illustr.)PIRENA. Lam. A genus of fresh-water shells, rejected by De Ferussac and other authors, who place Lamarck's two first species with Melanopsis, and his two last with Melania. Fig. 316, P. terebralis.PISIDIUM. Leach. A genus of river shells separated from Cyclas principally on account of a difference in the animal. The species of Pisidium, however, are less equilateral than the Cyclades, and the posterior or ligamentary side of the latter is the longer, while that of the former is the shorter. Fig. 112.PISIFORM. (Pisum, a pea;forma, shape.) Shaped like a pea or small globular body.PISUM. Megerle. (A pea.)Pisidium, Leach.PITHOHELIX. Sw. A sub-genus of "Geotrochus," Sw. Sw. p. 332.PITONELLUS. Montf.Rotella, Auct.PLACENTA. Schum.Placuna, Auct.PLACENTULA. Schum. A genus of microscopic Foraminifera.PLACUNA. Brug. (πλακους,placos, a cake.)Fam.Ostracea, Lam. and Bl.—Descr.Compressed, thin, equivalve, nearly equilateral, planorbicular, fibrous, foliaceous; hinge flat, with two diverging ribs in one valve, and two corresponding grooves in the other, containing the cartilage; muscular impressions one, large, circular, central, and one or two smaller in each valve.—Obs.The two best known species of this well defined genus are the P. Placenta, commonly called the Chinese Window Shell, and the P. Sella, called the Saddle Oyster, from the anterior margin being turned up so as to resemble a saddle. The genus may be known from all others by the diverging costa on the hinge. Placunanomia is the only genus resembling it in this respect, but this is easily distinguished by a perforation through the shell. Fig. 184, P. Placuna. These shells are used in China to glaze windows.PLACUNANOMIA. (Sw.PlacunaandAnomia.)Fam.Ostracea, Lam. and Bl.—Descr.Thin, foliaceous, compressed, sub-equivalve, sub-equilateral, irregular, flat near the umbones, plicated towards the margins, attached by a bony substance passing through a fissure in the lower valve; hinge flat, with two diverging ribs in one valve, corresponding with two diverging grooves, containing the cartilage, in the other; muscular impressions one in each valve, central, sub-orbicular.—Obs.The specimens from which Mr. Broderip described this singular genus, were brought by Mr. Cuming from the gulf of Dulce in Costa Rico. Another species is from one of the Philippine Islands. They partake of the characters of several genera, having the hinge of Placuna, and being attached by a process passing through the lower valve, like Anomia. P. Cumingii, fig. 189.PLAGIOSTOMA. Sow. Min. Con. (πλαγιος,plagios, oblique;στομα,stoma, mouth.)Fam.Pectenides, Lam. Palliobranchiata, Bl.—Descr.Sub-equivalve, inequilateral, oblique, auriculated on each side of the umbones, radiately striated; hinge straight in one valve, with a triangular notch in the other.—Obs.This genus, one species of which is spinous, and another smooth, is only known in a fossil state. It is found in the Lias and chalk. Fig. 176, P. spinosum.PLAIT or FOLD. A term applied to the prominences on the columellar lip of some univalve shells, particularly in the sub-family of Volutidæ.Ex.Voluta, fig. 433; Cymba, 434; and Melo, fig. 435.PLANARIA. Brown. A minute fossil resembling Planorbis in appearance, but differing in being a marine shell, and having a reflected outer lip. P. nitens, fig. 312, from Lea's Contributions to Geology.PLANAXIS. Lam. (Plana, flat; andaxis.)Fam.Turbinacea, Lam. Entomostomata, Bl.—Descr.Sub-ovate, pyramidal, solid; spire measuring ½ or ⅓ of the axis, consisting of few whorls; columella contiguous to the axis, flat, truncated, and separated from the outer lip by a short canal; outer lip thickened and denticulated within; operculum horny, thin, with a terminal nucleus.—Obs.This is a genus of small marine shells found in the West Indies, &c. Fig. 365, P. sulcata.PLANE. (Planus.) Flat, planed, as the columellar lip of Purpura, fig. 414.PLANORBICULAR, (Planus, flat;orbis, an orb.) Flat and circular, as Ammonites, fig. 478.PLANORBIS. Müll. (Planus, flat;orbis, an orb.)Fam.Lymnacea, Lam. and Bl.—Descr.Thin, horny, convolute, planorbicular, nearly symmetrical; spire compressed, concave, consisting of numerous gradually increasing whorls, which are visible on both sides; aperture transversely oval, or nearly round; peritreme entire; outer lip thin; inner lip distinct, spread over a part of the body whorl.—Obs.This is a genus of shells abounding in all climates in ditches and stagnant pools, not liable to be confounded with any other, excepting the discoidal species of Ampullaria, which may be distinguished by the aperture being broadest in the opposite direction. It is further to be remarked that the discoidal Ampullariæ are dextral shells, and the Planorbes are sinistral or reversed; and although the latter are sometimes so flat and orbicular that it is difficult to know which is the spiral side, it may nevertheless always be ascertained by a careful examination. Fossil species are found in the freshwater strata of the Isle of Wight, and the neighbourhood of Paris. Fig. 311, P. corneus.PLANORBULINA. D'Orb. A genus of microscopic Foraminifera.PLANULACEA. Bl. The second family of Cellulacea, Bl. The microscopic Foraminifera contained in this family are described as very much depressed, not spiral, chambered, cellular, and having the septa indicated by grooves on the external surface of the shell, which increase in length from the apex to the base: some of the small cellular cavities are to be seen on the margins. This family contains the genera Renulina and Peneroplis.PLANULARIA. Defr.Peneroplis, Montf. A genus of microscopic Foraminifera.PLANULINA. D'Orb. A genus of microscopic Foraminifera.PLANULITES. Lam.Discorbitesof the same author. A genus of microscopic Foraminifera.PLATIRIS. Lea. (πλατυς,platus, wide;ιρις,iris.) A genus including several species of Nayades, referred toIridina, Lam. The genus Platiris is divided into two sub-genera. Iridina, species which have crenulated margins; I. Ovata, I. exotica, Spatha, Lea; those with smooth or very slightly crenulated hinges, S. rubeus, S. Solenoides, Mycetopus, D'Orb. Fig. 151.PLATYLEPAS. (πλατυς,platus, wide;λεπας,lepas, rock.)Order.Sessile Cirripedes, Lam.Fam.Balanidea, Bl.—Descr.Conical, depressed, consisting of six valves, each divided internally by an angular plate jutting from the centre (like the buttress of a wall); operculum consisting of four valves in pairs.—Obs.This genus differs from Balanus, Coronula, &c. in the internal structure of the valves. De Blainville's description of Chthalamus partly agrees with this. Fig. 19.PLECTOPHORUS. Fer. (πληκτρον,plectron, spur;φορεω,phoreo, to carry.) A genus consisting of small testaceous appendages fixed on the posterior extremity of a species of slug. P. corninus, fig. 260.PLEIODON. Conrad.Iridina, Lam.Fam.Nayades, Lam.PLEKOCHEILUS. Guild.AuriculaCaprella, Lam.Carychiumundulatum, Leach. (Caprella, Nonnull.) This proposed genus is described as scarcely umbilical, dextral, oval, spiral; with the spire elevated, obtuse; the two last whorls very large, ventricose; aperture entire, elongated; columella with a single plait; the plait concave, inflected. Fig. 522, 523.PLEUROBRANCHUS. Cuv. (Πλευρα,pleura, the side;Branchiæ, gills.)Fam.Semiphyllidiana, Lam. Subaplysiacea, Bl.—Descr.Internal, thin, haliotoid, slightly convex towards the spiral apex; aperture entire.—Obs.This is a very light shell, delicately coloured, resembling Aplysia, but differing in the integrity of the margin. Fig. 232, P. membranaceus.PLEUROCERUS. Rafinesque. A genus very imperfectly described in the "Journal de Physique" as "oval, or pyramidal; aperture oblong; outer lip thin; inner lip truncated at the columella, which is smooth and tortuous, not umbilicated. Operculum horny or membranaceous." De Blainville, in giving this description, remarks that he has neither seen the animal nor the shell of this genus, which he imagines to have been formed from the "Paludine Coupée de M. Say."PLEURORYNCHUS. Phillips. (Πλευρα,pleura, the side;ρυγχος,rynchus, a beak.) A genus founded upon a very singular species ofCardium, distinguished by the short anterior side, and the elongation of the hinge line into auricular processes, which are truncated at the extremities. C. Hibernicum from the Black Rock near Dublin, which is vulgarly called Asses-hoof, and C. elongatum (Sow. Min. Con. vol. I. 82.), form part of this genus.PLEUROTOMA. Lam.Fam.Canalifera, Lam. Siphonostomata, Bl.—Descr.Fusiform, thick, in general ribbed or striated transversely; aperture oval, terminating anteriorly in an elongated canal; outer lip thin, with a fissure near its spiral extremity; columella smooth, nearly straight. Found principally in tropical climates.—Obs.This genus, which nearly resembles Fusus in other respects, may be known by the notch in the outer lip. The species differ in the length of the canal. Swainson has designated this genus a family, thus divided into genera: Brachytoma, in the description of which he says that the spire and aperture are of equal length, including the species strombiformis: Pleurotoma, in which the channel is so much lengthened, as to be little shorter than the spire: Clavatula, having the long narrow slit of Pleurotoma, but with a very short canal: Clavicantha, having the canal equally short, but the sinus or notch, instead of being linear and long, is short and wide; the surface is rough, and the whorls either coronated with prickles, or with compressed nodules resembling spines: Tomella, which has the spire and canal fusiform, but the spire of very few whorls, and the inner lip considerably thickened within where it joins the outer lip. Fig. 379, 389, P. marmorata; 381, P. Strombiformis, (Clavatula, Sw.)PLEUROTOMARIA. Defr.Fam.Turbinacea, Lam.—Descr.Turbinated, spiral; aperture sub-quadrate, with rounded angles; outer lip with a deep slit near its union with the spire.—Obs.This genus, which is only known in a fossil state, abounds in inferior Oolite, Oxford clay, and casts are found in a limestone bed in Norway. The Scissurellæ differ in being very minute shells, and are not so trochiform as the species of Pleurotomaria, P. reticulata, fig. 341.PLICACEA. Lam. A family of the order Trachelipoda, Lam. containing the following genera:
PHYLLONOTUS. Sw. A sub-genus of Murex, thus described: "Canal moderate; varices foliated, laciniated, compressed, or resembling leaves; inflatus. Mart. 102. fig. 980, eurystoma. Zool. Ill. ii. 100. imperialis. Ib. pl. 109." Sw. p. 296.
PHYSA. Drap. A genus formed for reversed species of Limnæa, Auct. Fig. 310, P. castanea.
PHYSETER. Humph.Solarium, Lam.
PILEOLUS. Cookson. (A little cap.)Fam.Neritacea, Lam.—Descr.Patelliform, with the apex sub-central, straight. In the lower disc, or under surface, the centre of which is rather raised or cushion-shaped, is placed the lateral, narrow, semilunar aperture, with the outer lip marginated and the inner lip crenulated.—Obs.This interesting genus is known only in a fossil state. Two species are found in the upper layer of Oolite, above the Bradford clay. The spire, although internal, connects this genus in some degree with Neritina. Still there is no danger of confounding them. Fig. 332, P. plicatus.
PILEOPSIS. Lam.Capulus, Montf.
PILLAR. The usual English name for the column which forms the axis of spiral shells, around which the whorls revolve. SeeColumella.
PINNA. Auct. (The fin of a fish.)Fam.Mytilacea, Lam.—Descr.Equivalve, inequilateral, oblique, wedge-shaped, thin, horny; umbones terminal; hinge rectilinear, without teeth; anterior margin sinuated, to admit the passage of a byssus; posterior margin truncated, gaping; muscular impressions two in each valve; posterior large, sub-central; anterior small, terminal, sometimes double.—Obs.The beautiful large shells of which this genus is composed, are possessed of a large, flowing, silky byssus, of which gloves and hose have been manufactured. They have received their name from their resemblance to the pectoral fins of some fishes. Some species attain very large dimensions, and measure two feet in length. A very improbable story is told with regard to animals of this genus, namely that a certain small species of crab is in the habit of taking refuge from its enemies in the shell of the Pinna, into which it is received with great hospitality and kindness by the "blind slug," which inhabits it. In return for which kindness, he occasionally goes abroad to procure food for both. On his return he knocks at the shell, which is opened to receive him, and they share the supplies together in convivial security! Some species are smooth, although the greater number are imbricated or crisped outside. P. saccata, fig. 162.
PINNATED. (FromPinna, a fin.) When a part of a shell is spread out and smooth, as in Rostellaria columbaria, fig. 403, it is said to bealated, or winged, but when the part which is spread is radiated or ribbed, like the fin of a fish, it ispinnated, as in Murex pinnatus, and Murex tripterus. (Conch. Illustr.)
PIRENA. Lam. A genus of fresh-water shells, rejected by De Ferussac and other authors, who place Lamarck's two first species with Melanopsis, and his two last with Melania. Fig. 316, P. terebralis.
PISIDIUM. Leach. A genus of river shells separated from Cyclas principally on account of a difference in the animal. The species of Pisidium, however, are less equilateral than the Cyclades, and the posterior or ligamentary side of the latter is the longer, while that of the former is the shorter. Fig. 112.
PISIFORM. (Pisum, a pea;forma, shape.) Shaped like a pea or small globular body.
PISUM. Megerle. (A pea.)Pisidium, Leach.
PITHOHELIX. Sw. A sub-genus of "Geotrochus," Sw. Sw. p. 332.
PITONELLUS. Montf.Rotella, Auct.
PLACENTA. Schum.Placuna, Auct.
PLACENTULA. Schum. A genus of microscopic Foraminifera.
PLACUNA. Brug. (πλακους,placos, a cake.)Fam.Ostracea, Lam. and Bl.—Descr.Compressed, thin, equivalve, nearly equilateral, planorbicular, fibrous, foliaceous; hinge flat, with two diverging ribs in one valve, and two corresponding grooves in the other, containing the cartilage; muscular impressions one, large, circular, central, and one or two smaller in each valve.—Obs.The two best known species of this well defined genus are the P. Placenta, commonly called the Chinese Window Shell, and the P. Sella, called the Saddle Oyster, from the anterior margin being turned up so as to resemble a saddle. The genus may be known from all others by the diverging costa on the hinge. Placunanomia is the only genus resembling it in this respect, but this is easily distinguished by a perforation through the shell. Fig. 184, P. Placuna. These shells are used in China to glaze windows.
PLACUNANOMIA. (Sw.PlacunaandAnomia.)Fam.Ostracea, Lam. and Bl.—Descr.Thin, foliaceous, compressed, sub-equivalve, sub-equilateral, irregular, flat near the umbones, plicated towards the margins, attached by a bony substance passing through a fissure in the lower valve; hinge flat, with two diverging ribs in one valve, corresponding with two diverging grooves, containing the cartilage, in the other; muscular impressions one in each valve, central, sub-orbicular.—Obs.The specimens from which Mr. Broderip described this singular genus, were brought by Mr. Cuming from the gulf of Dulce in Costa Rico. Another species is from one of the Philippine Islands. They partake of the characters of several genera, having the hinge of Placuna, and being attached by a process passing through the lower valve, like Anomia. P. Cumingii, fig. 189.
PLAGIOSTOMA. Sow. Min. Con. (πλαγιος,plagios, oblique;στομα,stoma, mouth.)Fam.Pectenides, Lam. Palliobranchiata, Bl.—Descr.Sub-equivalve, inequilateral, oblique, auriculated on each side of the umbones, radiately striated; hinge straight in one valve, with a triangular notch in the other.—Obs.This genus, one species of which is spinous, and another smooth, is only known in a fossil state. It is found in the Lias and chalk. Fig. 176, P. spinosum.
PLAIT or FOLD. A term applied to the prominences on the columellar lip of some univalve shells, particularly in the sub-family of Volutidæ.Ex.Voluta, fig. 433; Cymba, 434; and Melo, fig. 435.
PLANARIA. Brown. A minute fossil resembling Planorbis in appearance, but differing in being a marine shell, and having a reflected outer lip. P. nitens, fig. 312, from Lea's Contributions to Geology.
PLANAXIS. Lam. (Plana, flat; andaxis.)Fam.Turbinacea, Lam. Entomostomata, Bl.—Descr.Sub-ovate, pyramidal, solid; spire measuring ½ or ⅓ of the axis, consisting of few whorls; columella contiguous to the axis, flat, truncated, and separated from the outer lip by a short canal; outer lip thickened and denticulated within; operculum horny, thin, with a terminal nucleus.—Obs.This is a genus of small marine shells found in the West Indies, &c. Fig. 365, P. sulcata.
PLANE. (Planus.) Flat, planed, as the columellar lip of Purpura, fig. 414.
PLANORBICULAR, (Planus, flat;orbis, an orb.) Flat and circular, as Ammonites, fig. 478.
PLANORBIS. Müll. (Planus, flat;orbis, an orb.)Fam.Lymnacea, Lam. and Bl.—Descr.Thin, horny, convolute, planorbicular, nearly symmetrical; spire compressed, concave, consisting of numerous gradually increasing whorls, which are visible on both sides; aperture transversely oval, or nearly round; peritreme entire; outer lip thin; inner lip distinct, spread over a part of the body whorl.—Obs.This is a genus of shells abounding in all climates in ditches and stagnant pools, not liable to be confounded with any other, excepting the discoidal species of Ampullaria, which may be distinguished by the aperture being broadest in the opposite direction. It is further to be remarked that the discoidal Ampullariæ are dextral shells, and the Planorbes are sinistral or reversed; and although the latter are sometimes so flat and orbicular that it is difficult to know which is the spiral side, it may nevertheless always be ascertained by a careful examination. Fossil species are found in the freshwater strata of the Isle of Wight, and the neighbourhood of Paris. Fig. 311, P. corneus.
PLANORBULINA. D'Orb. A genus of microscopic Foraminifera.
PLANULACEA. Bl. The second family of Cellulacea, Bl. The microscopic Foraminifera contained in this family are described as very much depressed, not spiral, chambered, cellular, and having the septa indicated by grooves on the external surface of the shell, which increase in length from the apex to the base: some of the small cellular cavities are to be seen on the margins. This family contains the genera Renulina and Peneroplis.
PLANULARIA. Defr.Peneroplis, Montf. A genus of microscopic Foraminifera.
PLANULINA. D'Orb. A genus of microscopic Foraminifera.
PLANULITES. Lam.Discorbitesof the same author. A genus of microscopic Foraminifera.
PLATIRIS. Lea. (πλατυς,platus, wide;ιρις,iris.) A genus including several species of Nayades, referred toIridina, Lam. The genus Platiris is divided into two sub-genera. Iridina, species which have crenulated margins; I. Ovata, I. exotica, Spatha, Lea; those with smooth or very slightly crenulated hinges, S. rubeus, S. Solenoides, Mycetopus, D'Orb. Fig. 151.
PLATYLEPAS. (πλατυς,platus, wide;λεπας,lepas, rock.)Order.Sessile Cirripedes, Lam.Fam.Balanidea, Bl.—Descr.Conical, depressed, consisting of six valves, each divided internally by an angular plate jutting from the centre (like the buttress of a wall); operculum consisting of four valves in pairs.—Obs.This genus differs from Balanus, Coronula, &c. in the internal structure of the valves. De Blainville's description of Chthalamus partly agrees with this. Fig. 19.
PLECTOPHORUS. Fer. (πληκτρον,plectron, spur;φορεω,phoreo, to carry.) A genus consisting of small testaceous appendages fixed on the posterior extremity of a species of slug. P. corninus, fig. 260.
PLEIODON. Conrad.Iridina, Lam.Fam.Nayades, Lam.
PLEKOCHEILUS. Guild.AuriculaCaprella, Lam.Carychiumundulatum, Leach. (Caprella, Nonnull.) This proposed genus is described as scarcely umbilical, dextral, oval, spiral; with the spire elevated, obtuse; the two last whorls very large, ventricose; aperture entire, elongated; columella with a single plait; the plait concave, inflected. Fig. 522, 523.
PLEUROBRANCHUS. Cuv. (Πλευρα,pleura, the side;Branchiæ, gills.)Fam.Semiphyllidiana, Lam. Subaplysiacea, Bl.—Descr.Internal, thin, haliotoid, slightly convex towards the spiral apex; aperture entire.—Obs.This is a very light shell, delicately coloured, resembling Aplysia, but differing in the integrity of the margin. Fig. 232, P. membranaceus.
PLEUROCERUS. Rafinesque. A genus very imperfectly described in the "Journal de Physique" as "oval, or pyramidal; aperture oblong; outer lip thin; inner lip truncated at the columella, which is smooth and tortuous, not umbilicated. Operculum horny or membranaceous." De Blainville, in giving this description, remarks that he has neither seen the animal nor the shell of this genus, which he imagines to have been formed from the "Paludine Coupée de M. Say."
PLEURORYNCHUS. Phillips. (Πλευρα,pleura, the side;ρυγχος,rynchus, a beak.) A genus founded upon a very singular species ofCardium, distinguished by the short anterior side, and the elongation of the hinge line into auricular processes, which are truncated at the extremities. C. Hibernicum from the Black Rock near Dublin, which is vulgarly called Asses-hoof, and C. elongatum (Sow. Min. Con. vol. I. 82.), form part of this genus.
PLEUROTOMA. Lam.Fam.Canalifera, Lam. Siphonostomata, Bl.—Descr.Fusiform, thick, in general ribbed or striated transversely; aperture oval, terminating anteriorly in an elongated canal; outer lip thin, with a fissure near its spiral extremity; columella smooth, nearly straight. Found principally in tropical climates.—Obs.This genus, which nearly resembles Fusus in other respects, may be known by the notch in the outer lip. The species differ in the length of the canal. Swainson has designated this genus a family, thus divided into genera: Brachytoma, in the description of which he says that the spire and aperture are of equal length, including the species strombiformis: Pleurotoma, in which the channel is so much lengthened, as to be little shorter than the spire: Clavatula, having the long narrow slit of Pleurotoma, but with a very short canal: Clavicantha, having the canal equally short, but the sinus or notch, instead of being linear and long, is short and wide; the surface is rough, and the whorls either coronated with prickles, or with compressed nodules resembling spines: Tomella, which has the spire and canal fusiform, but the spire of very few whorls, and the inner lip considerably thickened within where it joins the outer lip. Fig. 379, 389, P. marmorata; 381, P. Strombiformis, (Clavatula, Sw.)
PLEUROTOMARIA. Defr.Fam.Turbinacea, Lam.—Descr.Turbinated, spiral; aperture sub-quadrate, with rounded angles; outer lip with a deep slit near its union with the spire.—Obs.This genus, which is only known in a fossil state, abounds in inferior Oolite, Oxford clay, and casts are found in a limestone bed in Norway. The Scissurellæ differ in being very minute shells, and are not so trochiform as the species of Pleurotomaria, P. reticulata, fig. 341.
PLICACEA. Lam. A family of the order Trachelipoda, Lam. containing the following genera:
1.Pyramidella.Pyramidal, with numerous whorls. Fig. 342.2.Tornatella.Cylindrical, with few whorls. Fig. 343, 344.3.Ringicula.Margin reflected. Fig. 540, 541.
1.Pyramidella.Pyramidal, with numerous whorls. Fig. 342.
2.Tornatella.Cylindrical, with few whorls. Fig. 343, 344.
3.Ringicula.Margin reflected. Fig. 540, 541.
PLICADOMUS. Sw. A sub-genus of Pupa, thus described: "spire moderate, regular and thick, but gradually conic; the tip obtuse; aperture perpendicular; inner lip wanting; outer lip semicircular; the margin dilated and reflected. P. sulcata, Chem. 135, f. 1231, 1232." Sw. p. 332.PLICATED. (Plicatus, folded.) Applied to spiral plaits on the columella of some shells.Ex.Voluta, fig. 433. Also to the angular bendings in the margins of some bivalve shells.Ex.Dendostrea, fig. 181.PLICATULA. Lam. (Plicatus, folded.)Fam.Pectenides, Lam. Sub-ostracea, Bl.—Descr.Irregular, sub-equivalve, sub-equilateral, attached by a small part of the surface of one valve, strongly plicated; umbones separated by a small, external ligamentary area; hinge with two cardinal teeth in each valve, two approximate in one valve, received between two distant in the other; cartilage placed between the cardinal teeth; muscular impressions one in each valve.—Obs.The cardinal teeth resembling those of Spondylus, distinguish this genus from others of the Lamarckian family Pectenides. Very few species are yet known, they are brought from the East and West Indies and the Philippine Islands. Fossil species are found in several of the supra-cretaceous beds. Fig. 178, P. gibbosa.PNEUMOBRANCHIA. Lam. The second section of the order Gasteropoda, Lam. containing the family Limacinea, fig. 256 to 263.PODOPSIS. Lam. This genus appears to have been described from specimens of a species of Spondylus, with the triangular disc broken out, so as to present a similarly shaped foramen, which was supposed to afford a passage for a large byssus.POLINICES. Montf. A genus composed ofNaticaMammilla, and other similar species, with mammillated spires, and the umbilicus filled with enamel. Fig. 327.POLLIA. Gray.Tritonidea, Sw. The name given by Gray was pre-occupied by a genus of Lepidopterous Insects.POLLICIPES. Leach. (Pollex, a thumb's breadth;pes, a foot.)Order.Pedunculated Cirripedes, Lam.—Descr.Conical, compressed, consisting of numerous valves, mostly in pairs, three or four pairs forming the principal part of the shell, and surrounded at the base by two or three rows of smaller valves, supported on a scaly, short pedicle.—Obs.This description will be found to exclude Scalpellum, and Smilium, the valves of which are more equal. The P. Mitellus, Auct. (fig. 37*), has been separated as a genus under the name of Mitellus by some authors, and it is certainly very different from P. polymerus, fig. 37, and P. cornucopia.POLLONTES. Montf.Miliola, Bl. A genus of microscopic Foraminifera.POLYBRANCHIATA. Bl. (Πολυς,polus, many;branchiæ, gills.) The fifth family of the order Lamellibranchiata, Bl. containing the genera Arca, Pectunculus and Nucula, which have a series of small teeth on the hinge.POLYDONTES. Montf. (Πολυς,polus, many;οδος,odos, tooth.) A species of Helix, shaped likeCarocolla, and having a number of teeth in the aperture.POLYGONAL. Many-sided.POLYGONUM. Schum. (Πολυς,polus, many;γωνια,gonia, an angle.) A genus composed of species ofTurbinella, Auct. which have large continuous costæ, so as to present the appearance of many-sided shells. T. polygonus, fig. 383. This generic name may be used to include all those species of Turbinella, Auct. which have very small folds on the columella.POLYGYRA. Say. A genus of Heliciform shells, characterized by the large number of close set whorls, constituting the spire.Ex.P. Septemvolvus, fig. 275, 276.POLYLEPAS. Bl. (Πολυς,polus, many;λεπας,lepas,rock.)Scalpellum, Auct.POLYMORPHINA. D'Orb. A genus of microscopic Foraminifera.POLYPHEMUS. Montf. A genus composed of species ofAchatina, Auct. which have elongated apertures, short spires, and an undulation in the outer lip. P. Glans, fig. 288.POLYPLAXIPHORA. Bl. The second class of the sub-type Malentozoa, Bl. containing the genus Chiton.POLYSTOMELLA. Lam. A genus of microscopic Foraminifera.POLYTHALAMACEA. Bl. (Πολυς,polus, many;Θαλαμος,thalamos, chambers.) The third order of Cephalophora, Bl. the shells of which are described as straight, more or less symmetrically convolute, divided into several chambers. The septa are sometimes, but not always, pierced by one or more siphons. This order is divided into the families, Orthocerata, Lituacea, Cristacea, Ammonacea, Nautilacea, Turbinacea, Turriculacea, all of which contain genera of chambered shells. De Blainville arranges these families according to the degree in which the spires revolve. The first being straight, as the Orthocerata, and the last being so closely coiled up, that the last whorl covers the rest, as in the Nautilacea.POLYTHALAMIA. Lam. The first division of the order Cephalopoda, Lam. containing the following families of chambered shells, viz. Orthocerata, Lituacea, Cristacea, Sphærulacea, Radiolata, Nautilacea, Ammonacea. Fig. 463 to 484.POLYTROPA. Sw. A genus of "Scolyminæ," Sw. thus described: "Bucciniform; but the base narrow, and ending in a straight and contracted, but rather short, channel; spire longer, or as long as the aperture; exterior folliculated, or tuberculated; inner lip flattened, as inPurpura; basal notch small, oblique; no internal channel; crispata. En. Méth. 419, f. 2. Chem. 187, f. 1802. Capilla, Pennant, pl. 72, f. 89, imbricata. Mart. 122. f. 1124. ? rugosa. Chem. f. 1473-4." Sw. p. 305.POLYXENES. Montf. A genus of microscopic Foraminifera.POMATIA. Gesner. (Gray, Syn. B. M. p. 133.) A genus of the family of "Cyclostomidæ," described as having "an elongated shell with reflexed lips, and a horny spiral operculum." Also a sub-genus of Snails, containingHelixpomatia, Auct. (Gray's Turton, p. 135.)PORNUS. Humph.Ampullaria, Lam.PORCELLANA. Adanson.Marginella, Auct.PORODRAGUS. Montf. A genus composed of species of Belemnites, placed by De Blainville in the section characterized as swelled near the apex, and straightened towards the base.POSIDONIA. Brong. A genus formed on the cast of a bivalve shell, common on schists from Dillemberg.POSTERIOR. (After,behind.) The posterior or hinder part of a bivalve shell, is that in which the siphonal tube of the animal is placed. It is known in the shell, by the direction of the curve in the umbones, which is from the posterior towards the anterior; also by the ligament, which is always placed on the posterior part of the hinge, when it exists only on one side of the umbones; and by the sinus (when there is one) in the palleal impression, which is always near the posterior muscular impression. In some shells, however, it is very difficult for a learner to trace these marks; such bivalves, for instance, as have the ligament spread out on both sides of the umbones; such as are nearly symmetrical, and have the umbones consequently straight, and a single muscular impression near the centre of the valve. The Brachiopodous bivalves have a different position, with relation to the animal, from the other bivalves, so that the hinge line is the posterior extremity, and the part where the valves open, is the anterior. The posterior extremity of the aperture of a spiral univalve shell, is that nearest to the spire. In patelliform shells the anterior and posterior extremities are distinguished by the muscular impression, which is annular, enclosing a central disc in the inner surface of the shell, excepting where it is interrupted by the place where the head of the animal lies, which of course is anterior. The posterior is markedp.in fig. 119, and 387. SeeAnterior.POSTERO-BASAL MARGIN of a bivalve shell is the posterior side of the margin opposite the hinge.POSTERO-DORSAL MARGIN is the posterior side of the hinge.POTAMIS or POTAMIDES. Brong. A genus of fresh-water shells resembling Cerithium in the characters of the aperture, but which may be known from that genus by the thick, horny epidermis with which they are coated. P. muricata, fig. 377. (Cerithium, Sow.) We think that these shells should be placed nearMelania.POTAMOMYA. A genus of shells resembling Corbula, in every respect except that of being inhabitants of fresh-water. Fig. 498, 499, represents one of these fresh-water Corbulæ.POTAMOPHILA. Sow. (Ποταμις,potamis, river;φιλιος,philios, choice.) "Conques fluviatiles," Lam.—Descr.Thick, equivalve, inequilateral, trigonal, covered with a greenish brown, smooth, horny epidermis; hinge thickened, broad, with one central, notched cardinal tooth in one valve, and two in the other, with indistinct lateral teeth; ligament large, supported on prominent fulcra; muscular impressions two in each valve, sub-orbicular.—Obs.The name given to this shell refers to its place of abode, being found in rivers. It is the Venus sub-viridis of some authors, although being a fresh-water shell, and having an incrassated hinge, and a smooth, thick epidermis, it is most distinct from that genus. It is described by Bowdich under the name Megadesma, on account of its large ligament, and by Lamarck under that of Galathæa, a name previously used by him for a genus of Crustacea. P. radiata, fig. 115. Megadesma appears to be the preferable name, since it has the right of priority over Potamophila. It is found in Africa.PRIAMUS. A genus composed ofAchatinaPriamus, Lam.BuccinumStercus—Pulicum, Chemn. Conch. 9. t. 120. f. 1026-7. This shell is ascertained to belong to a marine mollusc, having a horny operculum, and therefore is justly considered to form a distinct genus, allied to the Buccina and Struthiolariæ. Fig. 545.PRISODON. Schum.Hyria, &c. Auct. Fig. 144.PRODUCED. (Productus, prominent.) A term applied to the spire of univalve shells, or to any other prominent portion.PRODUCTA. Sow. (Productus, produced.)Fam.Brachiopoda, Lam.—Descr.Equilateral, inequivalve, thick, striated; one valve generally convex, with the margin inflected, produced; the other valve flat, or slightly convex, with the margin reflected; hinge rectilinear, transverse.—Obs.The peculiarity of this genus, from which it derives its name, is the manner in which the anterior margins of the valves are drawn out and overwrap each other. The genus is only known in a fossil state. Species occur in Mountain Limestone, and Transition Limestone of older date. P. depressa, fig. 206.PROSERPINA. Gray? Fig. 274, represents a small shell belonging to the Helix tribe, to which it is believed, Mr. Gray has applied the name Proserpina nitida. We do not know how the genus is defined.PROTO. Defr. A fossil shell resemblingTurritella, but having a spiral band reaching to the centre of each valve. P. terebralis, Bl.PSAMMOBIA. Lam.Fam.Nymphacea, Lam.—Descr.Transverse, oblong, slightly gaping at both ends; hinge with two cardinal teeth in one valve, one in the other; ligament supported upon a prominent fulcrum; muscular impressions two in each valve, sub-orbicular, distant; palleal impression with a large sinus; epidermis thin.—Obs.The genus thus described includesPsammotæaof Lamarck, which, according to him, only differs in the number of teeth, and which he says are but "Psammobies dégenerées." The difference appears to be accidental. This genus differs from Tellina in not having a posterior fold in the margin. Fig. 100. The species are found in temperate and tropical climates.PSAMMOCOLA. Bl. (ψαμμος,psammos, sand;cola, an inhabitant.) A name given by De Blainville to shells of the genusPsammobia, includingPsammotæaof Lamarck.PSAMMOTÆA. See Lam.Psammobia.PSEUDOLIVA. Sw. A genus of "Eburninæ," Sw. thus described: "Shell thick, oval, oliviform, ventricose; spire very short, acute; base with two parallel grooves, one of which forms a notch at the base of the outer lip; suture slightly channelled; inner lip very thick, and turning inwards; aperture with an internal canal. Connects theTurbinellidæwith theVolutidæ. P. plumbea, Chem. 188. f. 1806, 1807." Sw. p. 306.PSILOSTOMATA. Bl. The third family of Aporobranchiata, Bl. containing no genera of shells.PTEROCERAS. Auct. (Πτερον,pteron, a wing;κερας,ceras, horn.)Fam.Ailées, Lam.—Descr.Turrited, oval, ventricose, thick, tuberculated; spire short; aperture oval, terminating in a lengthened canal at both extremities; outer lip thickened, expanded, produced into horn-shaped, hollow, thickened spires, with an anterior sinus apart from the canal.—Obs.This genus, containing the shells commonly called Devil's Claws, Gouty Scorpions, Spiders, &c. is distinguished from Strombus by the digitations of the outer lip. No fossil species are known. Fig. 405, P. aurantiaca.PTEROCYCLOS. Benson. Syn. B. M. p. 133. A genus formed of species of Cyclostoma, Auct. which have "a groove or hole at the hinder part of the mouth."PTEROPODA. Lam. (Πτερον,pteron, a wing;πους,pous, a foot.) The first order of the class Mollusca, Lam. consisting of molluscs whose organs of locomotion consist of a pair of wing-shaped fins. This order contains the genera Hyalæa, Clio, Cleodora, Spiratella, Cymbulia, and Pneumoderma. To which may be added other genera enumerated in explanation of figures 220 to 226. They may be thus distinguished.
PLICADOMUS. Sw. A sub-genus of Pupa, thus described: "spire moderate, regular and thick, but gradually conic; the tip obtuse; aperture perpendicular; inner lip wanting; outer lip semicircular; the margin dilated and reflected. P. sulcata, Chem. 135, f. 1231, 1232." Sw. p. 332.
PLICATED. (Plicatus, folded.) Applied to spiral plaits on the columella of some shells.Ex.Voluta, fig. 433. Also to the angular bendings in the margins of some bivalve shells.Ex.Dendostrea, fig. 181.
PLICATULA. Lam. (Plicatus, folded.)Fam.Pectenides, Lam. Sub-ostracea, Bl.—Descr.Irregular, sub-equivalve, sub-equilateral, attached by a small part of the surface of one valve, strongly plicated; umbones separated by a small, external ligamentary area; hinge with two cardinal teeth in each valve, two approximate in one valve, received between two distant in the other; cartilage placed between the cardinal teeth; muscular impressions one in each valve.—Obs.The cardinal teeth resembling those of Spondylus, distinguish this genus from others of the Lamarckian family Pectenides. Very few species are yet known, they are brought from the East and West Indies and the Philippine Islands. Fossil species are found in several of the supra-cretaceous beds. Fig. 178, P. gibbosa.
PNEUMOBRANCHIA. Lam. The second section of the order Gasteropoda, Lam. containing the family Limacinea, fig. 256 to 263.
PODOPSIS. Lam. This genus appears to have been described from specimens of a species of Spondylus, with the triangular disc broken out, so as to present a similarly shaped foramen, which was supposed to afford a passage for a large byssus.
POLINICES. Montf. A genus composed ofNaticaMammilla, and other similar species, with mammillated spires, and the umbilicus filled with enamel. Fig. 327.
POLLIA. Gray.Tritonidea, Sw. The name given by Gray was pre-occupied by a genus of Lepidopterous Insects.
POLLICIPES. Leach. (Pollex, a thumb's breadth;pes, a foot.)Order.Pedunculated Cirripedes, Lam.—Descr.Conical, compressed, consisting of numerous valves, mostly in pairs, three or four pairs forming the principal part of the shell, and surrounded at the base by two or three rows of smaller valves, supported on a scaly, short pedicle.—Obs.This description will be found to exclude Scalpellum, and Smilium, the valves of which are more equal. The P. Mitellus, Auct. (fig. 37*), has been separated as a genus under the name of Mitellus by some authors, and it is certainly very different from P. polymerus, fig. 37, and P. cornucopia.
POLLONTES. Montf.Miliola, Bl. A genus of microscopic Foraminifera.
POLYBRANCHIATA. Bl. (Πολυς,polus, many;branchiæ, gills.) The fifth family of the order Lamellibranchiata, Bl. containing the genera Arca, Pectunculus and Nucula, which have a series of small teeth on the hinge.
POLYDONTES. Montf. (Πολυς,polus, many;οδος,odos, tooth.) A species of Helix, shaped likeCarocolla, and having a number of teeth in the aperture.
POLYGONAL. Many-sided.
POLYGONUM. Schum. (Πολυς,polus, many;γωνια,gonia, an angle.) A genus composed of species ofTurbinella, Auct. which have large continuous costæ, so as to present the appearance of many-sided shells. T. polygonus, fig. 383. This generic name may be used to include all those species of Turbinella, Auct. which have very small folds on the columella.
POLYGYRA. Say. A genus of Heliciform shells, characterized by the large number of close set whorls, constituting the spire.Ex.P. Septemvolvus, fig. 275, 276.
POLYLEPAS. Bl. (Πολυς,polus, many;λεπας,lepas,rock.)Scalpellum, Auct.
POLYMORPHINA. D'Orb. A genus of microscopic Foraminifera.
POLYPHEMUS. Montf. A genus composed of species ofAchatina, Auct. which have elongated apertures, short spires, and an undulation in the outer lip. P. Glans, fig. 288.
POLYPLAXIPHORA. Bl. The second class of the sub-type Malentozoa, Bl. containing the genus Chiton.
POLYSTOMELLA. Lam. A genus of microscopic Foraminifera.
POLYTHALAMACEA. Bl. (Πολυς,polus, many;Θαλαμος,thalamos, chambers.) The third order of Cephalophora, Bl. the shells of which are described as straight, more or less symmetrically convolute, divided into several chambers. The septa are sometimes, but not always, pierced by one or more siphons. This order is divided into the families, Orthocerata, Lituacea, Cristacea, Ammonacea, Nautilacea, Turbinacea, Turriculacea, all of which contain genera of chambered shells. De Blainville arranges these families according to the degree in which the spires revolve. The first being straight, as the Orthocerata, and the last being so closely coiled up, that the last whorl covers the rest, as in the Nautilacea.
POLYTHALAMIA. Lam. The first division of the order Cephalopoda, Lam. containing the following families of chambered shells, viz. Orthocerata, Lituacea, Cristacea, Sphærulacea, Radiolata, Nautilacea, Ammonacea. Fig. 463 to 484.
POLYTROPA. Sw. A genus of "Scolyminæ," Sw. thus described: "Bucciniform; but the base narrow, and ending in a straight and contracted, but rather short, channel; spire longer, or as long as the aperture; exterior folliculated, or tuberculated; inner lip flattened, as inPurpura; basal notch small, oblique; no internal channel; crispata. En. Méth. 419, f. 2. Chem. 187, f. 1802. Capilla, Pennant, pl. 72, f. 89, imbricata. Mart. 122. f. 1124. ? rugosa. Chem. f. 1473-4." Sw. p. 305.
POLYXENES. Montf. A genus of microscopic Foraminifera.
POMATIA. Gesner. (Gray, Syn. B. M. p. 133.) A genus of the family of "Cyclostomidæ," described as having "an elongated shell with reflexed lips, and a horny spiral operculum." Also a sub-genus of Snails, containingHelixpomatia, Auct. (Gray's Turton, p. 135.)
PORNUS. Humph.Ampullaria, Lam.
PORCELLANA. Adanson.Marginella, Auct.
PORODRAGUS. Montf. A genus composed of species of Belemnites, placed by De Blainville in the section characterized as swelled near the apex, and straightened towards the base.
POSIDONIA. Brong. A genus formed on the cast of a bivalve shell, common on schists from Dillemberg.
POSTERIOR. (After,behind.) The posterior or hinder part of a bivalve shell, is that in which the siphonal tube of the animal is placed. It is known in the shell, by the direction of the curve in the umbones, which is from the posterior towards the anterior; also by the ligament, which is always placed on the posterior part of the hinge, when it exists only on one side of the umbones; and by the sinus (when there is one) in the palleal impression, which is always near the posterior muscular impression. In some shells, however, it is very difficult for a learner to trace these marks; such bivalves, for instance, as have the ligament spread out on both sides of the umbones; such as are nearly symmetrical, and have the umbones consequently straight, and a single muscular impression near the centre of the valve. The Brachiopodous bivalves have a different position, with relation to the animal, from the other bivalves, so that the hinge line is the posterior extremity, and the part where the valves open, is the anterior. The posterior extremity of the aperture of a spiral univalve shell, is that nearest to the spire. In patelliform shells the anterior and posterior extremities are distinguished by the muscular impression, which is annular, enclosing a central disc in the inner surface of the shell, excepting where it is interrupted by the place where the head of the animal lies, which of course is anterior. The posterior is markedp.in fig. 119, and 387. SeeAnterior.
POSTERO-BASAL MARGIN of a bivalve shell is the posterior side of the margin opposite the hinge.
POSTERO-DORSAL MARGIN is the posterior side of the hinge.
POTAMIS or POTAMIDES. Brong. A genus of fresh-water shells resembling Cerithium in the characters of the aperture, but which may be known from that genus by the thick, horny epidermis with which they are coated. P. muricata, fig. 377. (Cerithium, Sow.) We think that these shells should be placed nearMelania.
POTAMOMYA. A genus of shells resembling Corbula, in every respect except that of being inhabitants of fresh-water. Fig. 498, 499, represents one of these fresh-water Corbulæ.
POTAMOPHILA. Sow. (Ποταμις,potamis, river;φιλιος,philios, choice.) "Conques fluviatiles," Lam.—Descr.Thick, equivalve, inequilateral, trigonal, covered with a greenish brown, smooth, horny epidermis; hinge thickened, broad, with one central, notched cardinal tooth in one valve, and two in the other, with indistinct lateral teeth; ligament large, supported on prominent fulcra; muscular impressions two in each valve, sub-orbicular.—Obs.The name given to this shell refers to its place of abode, being found in rivers. It is the Venus sub-viridis of some authors, although being a fresh-water shell, and having an incrassated hinge, and a smooth, thick epidermis, it is most distinct from that genus. It is described by Bowdich under the name Megadesma, on account of its large ligament, and by Lamarck under that of Galathæa, a name previously used by him for a genus of Crustacea. P. radiata, fig. 115. Megadesma appears to be the preferable name, since it has the right of priority over Potamophila. It is found in Africa.
PRIAMUS. A genus composed ofAchatinaPriamus, Lam.BuccinumStercus—Pulicum, Chemn. Conch. 9. t. 120. f. 1026-7. This shell is ascertained to belong to a marine mollusc, having a horny operculum, and therefore is justly considered to form a distinct genus, allied to the Buccina and Struthiolariæ. Fig. 545.
PRISODON. Schum.Hyria, &c. Auct. Fig. 144.
PRODUCED. (Productus, prominent.) A term applied to the spire of univalve shells, or to any other prominent portion.
PRODUCTA. Sow. (Productus, produced.)Fam.Brachiopoda, Lam.—Descr.Equilateral, inequivalve, thick, striated; one valve generally convex, with the margin inflected, produced; the other valve flat, or slightly convex, with the margin reflected; hinge rectilinear, transverse.—Obs.The peculiarity of this genus, from which it derives its name, is the manner in which the anterior margins of the valves are drawn out and overwrap each other. The genus is only known in a fossil state. Species occur in Mountain Limestone, and Transition Limestone of older date. P. depressa, fig. 206.
PROSERPINA. Gray? Fig. 274, represents a small shell belonging to the Helix tribe, to which it is believed, Mr. Gray has applied the name Proserpina nitida. We do not know how the genus is defined.
PROTO. Defr. A fossil shell resemblingTurritella, but having a spiral band reaching to the centre of each valve. P. terebralis, Bl.
PSAMMOBIA. Lam.Fam.Nymphacea, Lam.—Descr.Transverse, oblong, slightly gaping at both ends; hinge with two cardinal teeth in one valve, one in the other; ligament supported upon a prominent fulcrum; muscular impressions two in each valve, sub-orbicular, distant; palleal impression with a large sinus; epidermis thin.—Obs.The genus thus described includesPsammotæaof Lamarck, which, according to him, only differs in the number of teeth, and which he says are but "Psammobies dégenerées." The difference appears to be accidental. This genus differs from Tellina in not having a posterior fold in the margin. Fig. 100. The species are found in temperate and tropical climates.
PSAMMOCOLA. Bl. (ψαμμος,psammos, sand;cola, an inhabitant.) A name given by De Blainville to shells of the genusPsammobia, includingPsammotæaof Lamarck.
PSAMMOTÆA. See Lam.Psammobia.
PSEUDOLIVA. Sw. A genus of "Eburninæ," Sw. thus described: "Shell thick, oval, oliviform, ventricose; spire very short, acute; base with two parallel grooves, one of which forms a notch at the base of the outer lip; suture slightly channelled; inner lip very thick, and turning inwards; aperture with an internal canal. Connects theTurbinellidæwith theVolutidæ. P. plumbea, Chem. 188. f. 1806, 1807." Sw. p. 306.
PSILOSTOMATA. Bl. The third family of Aporobranchiata, Bl. containing no genera of shells.
PTEROCERAS. Auct. (Πτερον,pteron, a wing;κερας,ceras, horn.)Fam.Ailées, Lam.—Descr.Turrited, oval, ventricose, thick, tuberculated; spire short; aperture oval, terminating in a lengthened canal at both extremities; outer lip thickened, expanded, produced into horn-shaped, hollow, thickened spires, with an anterior sinus apart from the canal.—Obs.This genus, containing the shells commonly called Devil's Claws, Gouty Scorpions, Spiders, &c. is distinguished from Strombus by the digitations of the outer lip. No fossil species are known. Fig. 405, P. aurantiaca.
PTEROCYCLOS. Benson. Syn. B. M. p. 133. A genus formed of species of Cyclostoma, Auct. which have "a groove or hole at the hinder part of the mouth."
PTEROPODA. Lam. (Πτερον,pteron, a wing;πους,pous, a foot.) The first order of the class Mollusca, Lam. consisting of molluscs whose organs of locomotion consist of a pair of wing-shaped fins. This order contains the genera Hyalæa, Clio, Cleodora, Spiratella, Cymbulia, and Pneumoderma. To which may be added other genera enumerated in explanation of figures 220 to 226. They may be thus distinguished.
1.Atlanta.Shaped like Nautilus, symmetrical. Fig. 220.2.Spiratella.Spiral, not symmetrical. Fig. 224.3.Creseis.Straight, thorn-shaped. Fig. 222.4.Vaginula.Straight, widened in the centre; apex pointed. Fig. 225.5.Cuvieria.The same; apex blunt. Fig. 223.6.Cleodora.Aperture with three spines; apex recurved. Fig. 221.7.Hyalæa.Vaulted, open extremity, three-cornered; apex tridentate. Fig. 226.
1.Atlanta.Shaped like Nautilus, symmetrical. Fig. 220.
2.Spiratella.Spiral, not symmetrical. Fig. 224.
3.Creseis.Straight, thorn-shaped. Fig. 222.
4.Vaginula.Straight, widened in the centre; apex pointed. Fig. 225.
5.Cuvieria.The same; apex blunt. Fig. 223.
6.Cleodora.Aperture with three spines; apex recurved. Fig. 221.
7.Hyalæa.Vaulted, open extremity, three-cornered; apex tridentate. Fig. 226.
PTEROPODA. Bl. The second family of Nucleobranchiata, Bl. the shells of which are described as symmetrical, extremely thin, transparent, longitudinally enrolled, either forwards or backwards. The animals are remarkable for a pair of broad, flat, natatory organs or membranaceous fins, from which the family derives its name. It contains, in the system of De Blainville, the genera Atlanta, Spiratella, and Argonauta, to which may probably be addedPharetrium, König;Entalis, Defrance.PULLASTRA. Sow.Fam.Conques Marines, Lam.—Descr.Equivalve, ovate or oblong, transverse, inequilateral; hinge with three diverging cardinal teeth in each valve, notched at the terminations; muscular impressions two in each valve; palleal impression having a large sinus; ligament external, partly hidden by the dorsal margin.—Obs.This genus includes the Venerirupes of Lamarck, and several species of his Veneres, they are found in the sand on the shores of temperate and tropical climates. Fig. 120, P. textile.PULMONOBRANCHIATA. Bl. The first order of the first section of Paracephalophora monoica, containing the families Limnacea, Auriculacea, and Limacinea.PULVINITES. Defr. (Pulvinus, a cushion.)Fam.Malleacea, Lam.—Descr.Sub-equivalve, inequilateral, compressed, thin, slightly gaping posteriorly; one valve flat, the other rather concave; hinge linear, short, divided into perpendicular grooves; muscular impressions two, one sub-central, the other above it, nearer the hinge.—Obs.This fossil shell is imperfectly known, and it is difficult to give a sufficient reason for separating it from Perna. It comes from the Baculite limestone of Normandy. Fig. 170, P. Adansonii.PUNCTATED. (Punctatus, spotted or dotted.) For example, see Conus Nussatella. Fig. 460.PUNCTICULIS. Sw. A sub-genus of "Coronaxis," Sw. (Conus) described in Swainson's Malacology, page 311.PUNCTURELLA. Lowe.Cemoria, Leach.PUPA. Auct.Fam.Colimacea, Lam.; Limacinea, Bl.—Descr.Cylindrical, generally ribbed; spire long, obtuse, composed of numerous slowly increasing whorls; aperture sub-quadrate, rounded anteriorly, entire; outer lip thickened; columella plaited.—Obs.This genus is composed of land shells very variable in form, differing from Bulinus in the numerous slowly increasing whorls of the spire, and in the plicæ on the columella, and from Clausilia in the want of a clausium. Britain, Southern Europe, East and West Indies, Mexico, &c. P. Uva. Fig. 291.PUPELLA. Sw. A sub-genus of Clausilia. Lardn. Cyclop. Malac. p. 334.PUPILLA. Leach. A sub-genus of Pupa, P. marginata, Auct. (Gray's Turton, p. 196.)PUPINA. Vignard.Moulinsia, Grateloup.Fam.Colimacea, Lam.—Descr.Pupiform, sub-cylindrical; last whorl less than the preceding; surface brilliantly polished; suture of the spire enamelled; aperture circular; peritreme thickened; a notch at the base of the inner lip; operculum horny, spiral.—Obs.The species upon which this genus was originally founded, and described in the "Annal des Sciences Naturelles," tome 18, p. 439, (December 1829,) is a small pupiform shell, having nothing to distinguish it but the enamelled suture and the notch in the aperture; characters quite insufficient in themselves for the purpose of generic distinction; at the same time sufficient to lead M. De Ferussac to the suspicion of its having an operculum. The next species, described by Grateloup under the name of Moulinsia Nunezii, (Ann. Soc. Linn. Burd, Nov. 1840), presents more remarkable characters, having the spire turned backwards and the penultimate whorl disproportionately large. Seven additional species have been lately brought to this country from the Philippine Islands by Mr. Cuming. They will be described by the author in the Zoological Proceedings for 1841, and an illustrated monograph of the whole genus is published in the Thesaurus Conchyliorum, Part I, by the Author. It may be observed that in one of the new species, the notch in the peritreme almost disappears, leaving a very slight sinus. Fig. 524, 526, 527, 528.PURPURA. Auct. ("The shell-fish from which purple is taken," Plin.)Fam.Purpurifera, Lam. Entomostomata, Bl.—Descr.Oval or oblong, thick; spire for the most part short, sometimes rather longer; external surface generally sulcated, granulated, tuberculated or muricated; aperture long, oval, somewhat dilated, emarginated anteriorly; outer lip crenated, acute; columella flattened; operculum horny, with the nucleus lateral, thin towards the columella.—Obs.True Purpuræ to be found in the Lamarckian genera Buccinum, Ricinula, and others. They may be generally distinguished by the flatness of the columellar lip, and by the short canal or emargination, which is not reflected or raised, as in Buccinum. The species are very numerous and very variable in form, inhabiting the seas of temperate and tropical climates. The animals secrete a purple liquor, which has been used advantageously for dyeing; the origin of the famous Tyrian dye. Fig. 414, P. persica.PURPURIFERA. Lam. (Purpura, purple;fero, to carry.) A family belonging to the second section of Lamarck's order Trachelipoda, the shells of which are described as having a very short recurved, or ascending canal, or else only a notch between the inner and outer lips. The name Purpurifera has been given to the family because the animals which it includes, and particularly the genus Purpura, contain the colouring matter from which the ancients obtained the well known splendid purple. This family contains the following genera.
PTEROPODA. Bl. The second family of Nucleobranchiata, Bl. the shells of which are described as symmetrical, extremely thin, transparent, longitudinally enrolled, either forwards or backwards. The animals are remarkable for a pair of broad, flat, natatory organs or membranaceous fins, from which the family derives its name. It contains, in the system of De Blainville, the genera Atlanta, Spiratella, and Argonauta, to which may probably be addedPharetrium, König;Entalis, Defrance.
PULLASTRA. Sow.Fam.Conques Marines, Lam.—Descr.Equivalve, ovate or oblong, transverse, inequilateral; hinge with three diverging cardinal teeth in each valve, notched at the terminations; muscular impressions two in each valve; palleal impression having a large sinus; ligament external, partly hidden by the dorsal margin.—Obs.This genus includes the Venerirupes of Lamarck, and several species of his Veneres, they are found in the sand on the shores of temperate and tropical climates. Fig. 120, P. textile.
PULMONOBRANCHIATA. Bl. The first order of the first section of Paracephalophora monoica, containing the families Limnacea, Auriculacea, and Limacinea.
PULVINITES. Defr. (Pulvinus, a cushion.)Fam.Malleacea, Lam.—Descr.Sub-equivalve, inequilateral, compressed, thin, slightly gaping posteriorly; one valve flat, the other rather concave; hinge linear, short, divided into perpendicular grooves; muscular impressions two, one sub-central, the other above it, nearer the hinge.—Obs.This fossil shell is imperfectly known, and it is difficult to give a sufficient reason for separating it from Perna. It comes from the Baculite limestone of Normandy. Fig. 170, P. Adansonii.
PUNCTATED. (Punctatus, spotted or dotted.) For example, see Conus Nussatella. Fig. 460.
PUNCTICULIS. Sw. A sub-genus of "Coronaxis," Sw. (Conus) described in Swainson's Malacology, page 311.
PUNCTURELLA. Lowe.Cemoria, Leach.
PUPA. Auct.Fam.Colimacea, Lam.; Limacinea, Bl.—Descr.Cylindrical, generally ribbed; spire long, obtuse, composed of numerous slowly increasing whorls; aperture sub-quadrate, rounded anteriorly, entire; outer lip thickened; columella plaited.—Obs.This genus is composed of land shells very variable in form, differing from Bulinus in the numerous slowly increasing whorls of the spire, and in the plicæ on the columella, and from Clausilia in the want of a clausium. Britain, Southern Europe, East and West Indies, Mexico, &c. P. Uva. Fig. 291.
PUPELLA. Sw. A sub-genus of Clausilia. Lardn. Cyclop. Malac. p. 334.
PUPILLA. Leach. A sub-genus of Pupa, P. marginata, Auct. (Gray's Turton, p. 196.)
PUPINA. Vignard.Moulinsia, Grateloup.Fam.Colimacea, Lam.—Descr.Pupiform, sub-cylindrical; last whorl less than the preceding; surface brilliantly polished; suture of the spire enamelled; aperture circular; peritreme thickened; a notch at the base of the inner lip; operculum horny, spiral.—Obs.The species upon which this genus was originally founded, and described in the "Annal des Sciences Naturelles," tome 18, p. 439, (December 1829,) is a small pupiform shell, having nothing to distinguish it but the enamelled suture and the notch in the aperture; characters quite insufficient in themselves for the purpose of generic distinction; at the same time sufficient to lead M. De Ferussac to the suspicion of its having an operculum. The next species, described by Grateloup under the name of Moulinsia Nunezii, (Ann. Soc. Linn. Burd, Nov. 1840), presents more remarkable characters, having the spire turned backwards and the penultimate whorl disproportionately large. Seven additional species have been lately brought to this country from the Philippine Islands by Mr. Cuming. They will be described by the author in the Zoological Proceedings for 1841, and an illustrated monograph of the whole genus is published in the Thesaurus Conchyliorum, Part I, by the Author. It may be observed that in one of the new species, the notch in the peritreme almost disappears, leaving a very slight sinus. Fig. 524, 526, 527, 528.
PURPURA. Auct. ("The shell-fish from which purple is taken," Plin.)Fam.Purpurifera, Lam. Entomostomata, Bl.—Descr.Oval or oblong, thick; spire for the most part short, sometimes rather longer; external surface generally sulcated, granulated, tuberculated or muricated; aperture long, oval, somewhat dilated, emarginated anteriorly; outer lip crenated, acute; columella flattened; operculum horny, with the nucleus lateral, thin towards the columella.—Obs.True Purpuræ to be found in the Lamarckian genera Buccinum, Ricinula, and others. They may be generally distinguished by the flatness of the columellar lip, and by the short canal or emargination, which is not reflected or raised, as in Buccinum. The species are very numerous and very variable in form, inhabiting the seas of temperate and tropical climates. The animals secrete a purple liquor, which has been used advantageously for dyeing; the origin of the famous Tyrian dye. Fig. 414, P. persica.
PURPURIFERA. Lam. (Purpura, purple;fero, to carry.) A family belonging to the second section of Lamarck's order Trachelipoda, the shells of which are described as having a very short recurved, or ascending canal, or else only a notch between the inner and outer lips. The name Purpurifera has been given to the family because the animals which it includes, and particularly the genus Purpura, contain the colouring matter from which the ancients obtained the well known splendid purple. This family contains the following genera.
1.Cassis.Outer lip thick, reflected, denticulated, canal turned suddenly over the back; spire short; includingCassideaandCypræcassis. Fig. 410 to 412.2.Cassidaria.Canal turned gently upwards. Fig. 407, 408.3.Oniscia.Inner lip granulated; canal short. Fig. 409.4.Buccinum.Outer lip thickened not reflected; canal short; includingCylleneandPhos.Fig. 416, 421, 422, 425.5.Nassa.The same, with a notch or tooth at the extremity of the columella; includingCyclops. Fig. 423, 424.6.Dolium.Swelled, grooved spirally; outer lip not reflected. Fig. 420.7.Purpura.Aperture large; columellar lip flat; including Tritonidea. Fig. 414, 415.8.Monoceros.The same, with a tooth on the outer lip. Fig. 417.9.Concholepas.Patelliform; aperture as large as the shell. Fig. 417.10.Ricinula.Columellar and outer lips granulated, denticulated, outer lip digitated; includingTribulus. Fig. 413.11.Trichotropis.Hairs on the epidermis, along the keels. Fig. 429.12.Terebra.Elongated, with a spiral groove near the suture of the whorls. Fig. 428.13.Bullia.Short; aperture wide; outer lip marginated. Fig. 427.14.Eburna.Like Buccinum, but the outer lip not thickened. Fig. 426.15.Harpa.With varices at regular intervals. Fig. 419.
1.Cassis.Outer lip thick, reflected, denticulated, canal turned suddenly over the back; spire short; includingCassideaandCypræcassis. Fig. 410 to 412.
2.Cassidaria.Canal turned gently upwards. Fig. 407, 408.
3.Oniscia.Inner lip granulated; canal short. Fig. 409.
4.Buccinum.Outer lip thickened not reflected; canal short; includingCylleneandPhos.Fig. 416, 421, 422, 425.
5.Nassa.The same, with a notch or tooth at the extremity of the columella; includingCyclops. Fig. 423, 424.
6.Dolium.Swelled, grooved spirally; outer lip not reflected. Fig. 420.
7.Purpura.Aperture large; columellar lip flat; including Tritonidea. Fig. 414, 415.
8.Monoceros.The same, with a tooth on the outer lip. Fig. 417.
9.Concholepas.Patelliform; aperture as large as the shell. Fig. 417.
10.Ricinula.Columellar and outer lips granulated, denticulated, outer lip digitated; includingTribulus. Fig. 413.
11.Trichotropis.Hairs on the epidermis, along the keels. Fig. 429.
12.Terebra.Elongated, with a spiral groove near the suture of the whorls. Fig. 428.
13.Bullia.Short; aperture wide; outer lip marginated. Fig. 427.
14.Eburna.Like Buccinum, but the outer lip not thickened. Fig. 426.
15.Harpa.With varices at regular intervals. Fig. 419.
PUSIA. Sw. A sub-genus of Tiara (Mitra.) (Sw. Malac. p. 320.)PUSIODON. Sw. A genus of "Lucerninæ," Sw. (Helix) thus described: "Shell flattened, smooth; the body-whorl large, and much dilated at the aperture; spire small, flat, of three or four contracted whorls; aperture very oblique, sinuated, or obsoletely toothed at the base of the outer lip, which is spreading and sub-reflected; inner lip obsolete; umbilicus open. Zonaria Chemn. 132. f. 1188. auriculata Zool. Ill. I. pl. 6." Sw. Malac. p. 330.PUSIOSTOMA. Sw. A genus of the family "Columbellinæ." Sw. Thus described: "general form of Columbella, but the outer lip is only toothed in the middle, where it is greatly thickened; inner lip convex between the granular teeth; punctata, E. M. 374. f. 4. mendicaria, 375. f. 10. turturina, 314. f. 2. fulgurans. Lam." Sw. Malac. p. 313.PUSTULARIA. Sw. A genus of "Cypræinæ," Sw. thus described: "Shell generally marked by elevated pustules; aperture narrow and linear; the extremities more or less produced; the teeth continued beyond, and frequently forming elevated striæ across the lips. P. Cicercula, P. Globulus." Sw. Malac. p. 324.PYGMÆA. Humph.Columbella, Auct.PYLORIDEA. Bl. The ninth family of the order Lamellibranchiata, Bl. the shells of which are described as nearly always regular, rarely otherwise, nearly always equivalve, gaping at both extremities; hinge incomplete, the teeth becoming gradually obsolete; two distinct muscular impressions; palleal impression very flexuous posteriorly. This family is divided into: Section 1. Ligament internal; Pandora, Thracia, Anatina, Mya, Lutricola. Section 2. Ligament external; Psammocola, Soletellina, Solen, Sanguinolaria, Solenocurtus, Solenimya, Panopæa, Glycimeris, Saxicava, Byssomya, Rhomboides, Hiatella, Gastrochæna, Clavagella, Aspergillum.PYRAMIDAL. (Pyramidalis.) Resembling a pyramid in form.Ex.Cerithium Telescopium, fig. 378.PYRAMIDELLA. Lam. (A little pyramid.)Fam.Plicacea, Lam.Auriculacea, Bl.—Descr.Pyramidal, smooth, polished; spire long, pointed, composed of numerous whorls; aperture small, modified by the last whorl, rounded anteriorly; outer lip slightly expanded; columella tortuous, with several folds. This is a genus of small, polished, marine shells. Pyramidella Terebellum, fig. 342.PYRAZUS. Montf.Potamis, Brongniart.PYRELLA. Sw. A genus consisting of Turbinella Spirilla, Auct. and similar species, having a long channel, a pyriform outline, and one strong plait at the base of the columella, the apex of the spire is enlarged. P. Spirillus, fig. 384. (The proper term would be Spirilla.)PYRIFORM. (Pyrum, a pear;forma, shape.) Shaped like a pear, i. e. large and rounding at one end, and gradually tapering at the other.Ex.Pyrula, fig. 390.PYRGO. Defr. A genus of microscopic Foraminifera.PYRGOMA. Auct. (Πυργος,pyrgus, a tower.)Order, Sessile Cirripedes, Lam.—Descr.Composed of a single conical, hollow paries, with a small aperture closed by an operculum of four valves, and supported upon a cup-shaped base.—Obs.The genera into which Leach has divided this genus are Pyrgoma, Adna, and Megatrema; his genera Nobia and Savignium differ in having but two valves for the operculum. Pyrgoma differs from Creusia in having the body of the shell, i. e. the parietal cone, simple, not divided into valves. Fig. 31.PYRGOPOLON. De Montfort's figure of this genus appears as if it had been drawn from the nucleus of a Belemnite.PYRULA. Auct. (A little pear.)Fam.Canalifera, Lam. Siphonostomata, Bl.—Descr.Thin, oblong, pyriform, ventricose towards the spire, gradually tapering towards the anterior of the aperture, spire short, consisting of few volutions; aperture wide, terminating in a long, narrow, open, canal; columella smooth, elegantly tortuous.—Obs.The above description includes all the true Fig shells, which present a most graceful form; the contour partaking of the peculiar curve, called by painters the line of beauty. P. Ficus, fig. 390.PYRUM. Humph.Pyrula, Lam.QUADRATE. (Quadratus.) Square, applied when the outline of shells is formed by nearly straight lines meeting at right angles.QUADRILATERAL. Four-sided.QUINQUELOCULINA. D'Orbigny. A genus of microscopic Foraminifera.RADIATING. (Radians.) A term applied to the ribs, striæ, bands of colours, &c. when they meet in a point at the umbones of a bivalve shell, and spread out towards the ventral margin.—Ex.The bands of colour in Tellina radiata, fig. 105.RADICATED. (Radix, a root.) Attached, and as it were rooted by means of a fibrous byssus.RADIOLATA. Lam. A family belonging to the order Cephalopoda, Lam. The shells belonging to it are described as discoidal, with the spire central, and the chambers radiating from the centre to the circumference. This family contains the genera Rotalina, Lenticulina, and Placentula.RADIOLITES. A genus belonging to the family of Rudistes, differing from Sphærulites, in having both the valves more conical.RADIUS. Montf. A genus composed ofOvulumVolva, Auct. and other similar species, having a long attenuated canal at each extremity. Fig. 442.RADIX. Montf. A genus composed of species ofLimnæa, having a short spire and wide aperture.—Ex.L. aperta, fig. 309.RAMIFIED. (Ramus, a branch.) Branched out.—Ex.The varices of some Murices, &c.RAMPHIDOMA. Schum.Pollicipes, Leach.RAMOSE. (Ramosus, branched.) Spread out into branches.Ex.Murex inflatus, fig. 395.RANELLA. Auct. (Rana, a frog.)Fam. Canalifera,Lam.Siphonostomata, Bl.—Descr.Oval or oblong, depressed, thick, with two rows of continuous varices, skirting the outline, one on each side; spire rather short, pyramidal, acute, aperture oval, terminating in a canal at each extremity; outer lip thickened within, crenulated, or denticulated, forming an external varix; inner lip spread over a portion of the body whorl.—Obs.The shells composing this well-defined genus, are for the most part covered with tuberculations, and granulations, and from the colour and squat shape of some species, have been likened to frogs. The Ranellæ are mostly inhabitants of the East Indian seas. The few fossil species known, occur in the tertiary beds. The two continuous rows of varices skirting the spire, distinguish this genus from Triton, which it nearly approaches, and into which some species run by imperceptible gradations. Fig. 393, 394. Many new species were brought to this country by Mr. Cuming, and are represented in parts 84, 85, 88, 89, 92, 93, of the author's Conchological Illustrations.RANGIA. Desmoulins.Gnathodon, Gray.RAPANUS. Schum.? A genus consisting of species ofPyrula, Auct. which are thin, much inflated, with short canals. Fig. 389, P. papyracea.RAPELLA. Sw. A genus of "Pyrulinæ," Sw. thus described: "Shell ventricose, generally thin, almost globose; the base suddenly contracted, and forming a short canal, the channel almost obsolete; umbilicus large, partly concealed by the inner lip. R. papyracea. En. Méth. 436, f. 1." Sw. p. 307.Rapanus, Schum. Fig. 389.RAPHANISTER. Montf. A species of madrepore, described as a shell.RAPUM. Humph.Turbinella, Lam.RAZOR SHELL. A common name by which shells of the genus Solen, are known in the market.RECTILINEAR. (Rectus, right;linea, a line.) In a straight line.Ex.The hinge of Byssoarca Noæ, fig. 132.RECURVED. (Re, back;curvo, to bend.) Turned backwards; the term, when applied to symmetrical conical univalves, is used to signify that the apex is turned towards the posterior margin, as in Emarginula, fig. 241.REFLECTED. (Reflected, to fold back.) Turned, or folded backwards.Ex.The edge of the outer lip in Bulinus, fig. 282, isreflected, while that of Cypræa, fig. 445 to 450, isinflected.REMOTE. (Remotus, distant.) Remote lateral teeth in a bivalve shell, are those that are placed at a distance from the cardinal teeth.Ex.The lateral teeth of Aphrodita, (fig. 123.) are remote; those of Donax, (fig. 108) are near.RENIELLA. Sw. A sub-genus of Malleus. Lardn. Cyclop. Malac. p. 886. Gray states it to be only a distorted specimen of Vulsella, Syn. B. M. p. 145.RENIFORM. (Ren, a kidney;forma, shape.) Shaped like a kidney.Ex.The aperture of Ampullaria, fig. 318.RENULINA. Lam. A genus of microscopic Foraminifera.REOPHAX. Montf. A genus of microscopic Orthocerata, Bl.REPENT. (Repens, creeping.) A term applied to those shells, which, being attached by the whole length of their shell, give the idea of creeping or crawling.Ex.Vermilia, fig. 7.RETICULATED. (Reticulatus.) Resembling net-work.RETIFERA. Bl. The first family of the order Cervicobranchiata, Bl. containing the genus Patella.REVERSED orSinistral Shells, are those in which the aperture is on the left side of the shell, while it is held with the mouth downwards, and towards the observer.Ex.Balea, fig. 296. Attached bivalves are said to be reversed, when the left valve is free, instead of the right; a circumstance which sometimes occurs in Chama and Ostrea.RHEDA. Humph.Hyalæa, Lam.RHINOCLAVIS. Sw. A genus of "Cerithinæ," Sw. thus described: "channel curved backwards, in an erect position; inner lip very thick, with a tumid margin; pillar generally with a central plait; operculum ear-shaped; lineatum. En. M. 443, fig. 3, Vertagus. Ib. f. 2, subulatum. Lam. No. 23, fasciatum. Mart. 157, f. 1481. obeliscus, En. Méth. 443, f. 4; aluco, Ib. f. 5, (Aberrant,) semi-granosum. Ib. 443, f. 1, asperum. Mart. 157, f. 1483."RHINOCURUS. Montf. A genus of microscopic Foraminifera.RHINODOMUS. Sw. A genus of "Scolyminæ," Sw. thus described: No internalgroove; shell clavate; the spire longer than, or equal with the aperture; the whorls with ridges or longitudinal varices, and rendered hispid by transverse grooves; inner lip wanting; pillar with a terminal fold; aperture striated; outer lip with a basal sinus. R. senticosus, Chem. tab. 193. f. 1864-1866.RHIZORUS. Montf. A genus described from a microscopic shell, appearing to be a cylindrical Bulla.RHODOSTOMA. Sw. A sub-genus of "Turbininæ," Sw. p. 344.RHOMBOIDAL. (ῥομβοειδος,rhomboeidus.) Having a rhombic form, i. e. four-sided; two sides meeting at acute, two at obtuse, angles. Conchologists are not very strict in the application of this term, for, indeed, a perfect rhomboidal figure could not be found among all the testaceous productions of the sea.RHOMBOIDES. Bl. A genus described as resembling Byssomya in the shell, but differing in the animal.Mytilusrugosus, Gmelin.Hypogæabarbata, Poli.RHOMBUS. Montf. (ῥομβος,rhombos, a rhomb.) A genus consisting of species ofConus, having a rhomboidal or quadrilateral form and a coronated spire.Ex.Conus nocturnus, fig. 459.RICINULA. Lam. (Resembling the seed-vessel of theRicinus.)Fam.Purpurifera, Lam. Entomostomata, Bl.—Descr.Sub-ovate, thick, tuberculated; spire short; aperture narrow, terminating anteriorly in a short canal; outer-lip thickened, denticulated within, digitated without; columellar lip spread over a portion of the body whorl, and granulated.—Obs.This interesting genus is composed of some neat little shells allied to Purpura, from which they are distinguished by the finger-like branching of the outer lip, and the granulations of the columella. Fig. 413, R. Horrida.RIGHT. SeeDextral.RIMULA. Defr. A genus consisting of a minute species ofEmarginula, Auct. which has a fissure near the margin, but not reaching it. R. Blainvillii, fig. 243.RIMULINA. D'Orbigny. A genus of microscopic Foraminifera.RINGICULA. Deshayes. A genus founded on Auricula ringens of Lamarck and several small fossils, resembling in some respects Pedipes of Adanson; they would belong to Tornatella, were it not for the lips being thickened and marginated, fig. 540, A. ringens.RISSOA. Freminville.Fam.Ellipsostomata, Bl. Melaniana, Lam.—Descr.Oblong, turrited, acuminated; spire long, consisting of numerous whorls; aperture round or oval, pointed posteriorly, dilated anteriorly; outer lip slightly thickened, emarginated, operculum horny.—Obs.The Rissoæ are small white, marine shells, considered by some authors as resembling Melaniæ, but placed by Sowerby near the Scalariæ. They are principally from the shores of the Mediterranean, and are also very abundant on the British shores, as well as the East and West Indian. Fig. 346, R. reticulata.ROBULUS. Montf. A genus of microscopic Foraminifera.ROLLUS. Montf. A genus composed ofConusGeographus, Auct. fig. 462, and other species, rather cylindrical in form, and having a coronated spire.ROSALINA. D'Orb. A genus of microscopic Foraminifera.ROSTELLARIA. (Fromrostrum, a beak.)Fam.Alatæ, Lam. Siphonostomata, Bl.—Descr.Turrited, fusiform, thick, smooth or ribbed; aperture oval, terminating anteriorly in a long canal, posteriorly in a channel running up the spire; outer lip dilated, thickened, sometimes digitated, running up all or part of the spire, with a sinus near the anterior canal; inner lip smooth, spread over part of the body whorl and of the spire. The Red Sea and the Indian Ocean produce the few known species of this genus.—Obs.Hippochrenesis the name given by De Montfort, to those fossil species which have the outer lip simple and very much dilated. R. curvirostrum, fig. 412.Aporrhaisis a name given to another proposed genus, composed of Rostellaria pes-pelecani, Auct. fig. 404. and similar species.ROSTRATED. (Fromrostrum, a beak.) Having one or more protruding points, as Tellina rostrata.ROTALIA. Lam. A genus of microscopic Foraminifera. The same as Rotalites of De Montfort.ROTELLA. Lam. (A little wheel.)Fam.Turbinacea, Lam.—Descr.Orbicular, generally smooth, shining; spire conical, depressed, short; aperture subtrigonal; outer lip thin, angulated near the centre; inner lip spread over the surface of the whorls, forming a thickened disc. Operculum horny, orbicular, spiral, with numerous whorls.—Obs.The pretty little shells thus described are found in seas of tropical climates. They are distinguished from other genera of the family by their lenticular form and the orbicular callosity of the under surface. Fig. 357, R. vestiaria.RUDISTES. Lam. A family of the order Conchifera Monomyaria, Lam. the shells of which are described as irregular, very inequivalve, without distinct umbones; the ligament, hinge and animal entirely unknown. The shells contained in this family may be thus distinguished.
PUSIA. Sw. A sub-genus of Tiara (Mitra.) (Sw. Malac. p. 320.)
PUSIODON. Sw. A genus of "Lucerninæ," Sw. (Helix) thus described: "Shell flattened, smooth; the body-whorl large, and much dilated at the aperture; spire small, flat, of three or four contracted whorls; aperture very oblique, sinuated, or obsoletely toothed at the base of the outer lip, which is spreading and sub-reflected; inner lip obsolete; umbilicus open. Zonaria Chemn. 132. f. 1188. auriculata Zool. Ill. I. pl. 6." Sw. Malac. p. 330.
PUSIOSTOMA. Sw. A genus of the family "Columbellinæ." Sw. Thus described: "general form of Columbella, but the outer lip is only toothed in the middle, where it is greatly thickened; inner lip convex between the granular teeth; punctata, E. M. 374. f. 4. mendicaria, 375. f. 10. turturina, 314. f. 2. fulgurans. Lam." Sw. Malac. p. 313.
PUSTULARIA. Sw. A genus of "Cypræinæ," Sw. thus described: "Shell generally marked by elevated pustules; aperture narrow and linear; the extremities more or less produced; the teeth continued beyond, and frequently forming elevated striæ across the lips. P. Cicercula, P. Globulus." Sw. Malac. p. 324.
PYGMÆA. Humph.Columbella, Auct.
PYLORIDEA. Bl. The ninth family of the order Lamellibranchiata, Bl. the shells of which are described as nearly always regular, rarely otherwise, nearly always equivalve, gaping at both extremities; hinge incomplete, the teeth becoming gradually obsolete; two distinct muscular impressions; palleal impression very flexuous posteriorly. This family is divided into: Section 1. Ligament internal; Pandora, Thracia, Anatina, Mya, Lutricola. Section 2. Ligament external; Psammocola, Soletellina, Solen, Sanguinolaria, Solenocurtus, Solenimya, Panopæa, Glycimeris, Saxicava, Byssomya, Rhomboides, Hiatella, Gastrochæna, Clavagella, Aspergillum.
PYRAMIDAL. (Pyramidalis.) Resembling a pyramid in form.Ex.Cerithium Telescopium, fig. 378.
PYRAMIDELLA. Lam. (A little pyramid.)Fam.Plicacea, Lam.Auriculacea, Bl.—Descr.Pyramidal, smooth, polished; spire long, pointed, composed of numerous whorls; aperture small, modified by the last whorl, rounded anteriorly; outer lip slightly expanded; columella tortuous, with several folds. This is a genus of small, polished, marine shells. Pyramidella Terebellum, fig. 342.
PYRAZUS. Montf.Potamis, Brongniart.
PYRELLA. Sw. A genus consisting of Turbinella Spirilla, Auct. and similar species, having a long channel, a pyriform outline, and one strong plait at the base of the columella, the apex of the spire is enlarged. P. Spirillus, fig. 384. (The proper term would be Spirilla.)
PYRIFORM. (Pyrum, a pear;forma, shape.) Shaped like a pear, i. e. large and rounding at one end, and gradually tapering at the other.Ex.Pyrula, fig. 390.
PYRGO. Defr. A genus of microscopic Foraminifera.
PYRGOMA. Auct. (Πυργος,pyrgus, a tower.)Order, Sessile Cirripedes, Lam.—Descr.Composed of a single conical, hollow paries, with a small aperture closed by an operculum of four valves, and supported upon a cup-shaped base.—Obs.The genera into which Leach has divided this genus are Pyrgoma, Adna, and Megatrema; his genera Nobia and Savignium differ in having but two valves for the operculum. Pyrgoma differs from Creusia in having the body of the shell, i. e. the parietal cone, simple, not divided into valves. Fig. 31.
PYRGOPOLON. De Montfort's figure of this genus appears as if it had been drawn from the nucleus of a Belemnite.
PYRULA. Auct. (A little pear.)Fam.Canalifera, Lam. Siphonostomata, Bl.—Descr.Thin, oblong, pyriform, ventricose towards the spire, gradually tapering towards the anterior of the aperture, spire short, consisting of few volutions; aperture wide, terminating in a long, narrow, open, canal; columella smooth, elegantly tortuous.—Obs.The above description includes all the true Fig shells, which present a most graceful form; the contour partaking of the peculiar curve, called by painters the line of beauty. P. Ficus, fig. 390.
PYRUM. Humph.Pyrula, Lam.
QUADRATE. (Quadratus.) Square, applied when the outline of shells is formed by nearly straight lines meeting at right angles.
QUADRILATERAL. Four-sided.
QUINQUELOCULINA. D'Orbigny. A genus of microscopic Foraminifera.
RADIATING. (Radians.) A term applied to the ribs, striæ, bands of colours, &c. when they meet in a point at the umbones of a bivalve shell, and spread out towards the ventral margin.—Ex.The bands of colour in Tellina radiata, fig. 105.
RADICATED. (Radix, a root.) Attached, and as it were rooted by means of a fibrous byssus.
RADIOLATA. Lam. A family belonging to the order Cephalopoda, Lam. The shells belonging to it are described as discoidal, with the spire central, and the chambers radiating from the centre to the circumference. This family contains the genera Rotalina, Lenticulina, and Placentula.
RADIOLITES. A genus belonging to the family of Rudistes, differing from Sphærulites, in having both the valves more conical.
RADIUS. Montf. A genus composed ofOvulumVolva, Auct. and other similar species, having a long attenuated canal at each extremity. Fig. 442.
RADIX. Montf. A genus composed of species ofLimnæa, having a short spire and wide aperture.—Ex.L. aperta, fig. 309.
RAMIFIED. (Ramus, a branch.) Branched out.—Ex.The varices of some Murices, &c.
RAMPHIDOMA. Schum.Pollicipes, Leach.
RAMOSE. (Ramosus, branched.) Spread out into branches.Ex.Murex inflatus, fig. 395.
RANELLA. Auct. (Rana, a frog.)Fam. Canalifera,Lam.Siphonostomata, Bl.—Descr.Oval or oblong, depressed, thick, with two rows of continuous varices, skirting the outline, one on each side; spire rather short, pyramidal, acute, aperture oval, terminating in a canal at each extremity; outer lip thickened within, crenulated, or denticulated, forming an external varix; inner lip spread over a portion of the body whorl.—Obs.The shells composing this well-defined genus, are for the most part covered with tuberculations, and granulations, and from the colour and squat shape of some species, have been likened to frogs. The Ranellæ are mostly inhabitants of the East Indian seas. The few fossil species known, occur in the tertiary beds. The two continuous rows of varices skirting the spire, distinguish this genus from Triton, which it nearly approaches, and into which some species run by imperceptible gradations. Fig. 393, 394. Many new species were brought to this country by Mr. Cuming, and are represented in parts 84, 85, 88, 89, 92, 93, of the author's Conchological Illustrations.
RANGIA. Desmoulins.Gnathodon, Gray.
RAPANUS. Schum.? A genus consisting of species ofPyrula, Auct. which are thin, much inflated, with short canals. Fig. 389, P. papyracea.
RAPELLA. Sw. A genus of "Pyrulinæ," Sw. thus described: "Shell ventricose, generally thin, almost globose; the base suddenly contracted, and forming a short canal, the channel almost obsolete; umbilicus large, partly concealed by the inner lip. R. papyracea. En. Méth. 436, f. 1." Sw. p. 307.Rapanus, Schum. Fig. 389.
RAPHANISTER. Montf. A species of madrepore, described as a shell.
RAPUM. Humph.Turbinella, Lam.
RAZOR SHELL. A common name by which shells of the genus Solen, are known in the market.
RECTILINEAR. (Rectus, right;linea, a line.) In a straight line.Ex.The hinge of Byssoarca Noæ, fig. 132.
RECURVED. (Re, back;curvo, to bend.) Turned backwards; the term, when applied to symmetrical conical univalves, is used to signify that the apex is turned towards the posterior margin, as in Emarginula, fig. 241.
REFLECTED. (Reflected, to fold back.) Turned, or folded backwards.Ex.The edge of the outer lip in Bulinus, fig. 282, isreflected, while that of Cypræa, fig. 445 to 450, isinflected.
REMOTE. (Remotus, distant.) Remote lateral teeth in a bivalve shell, are those that are placed at a distance from the cardinal teeth.Ex.The lateral teeth of Aphrodita, (fig. 123.) are remote; those of Donax, (fig. 108) are near.
RENIELLA. Sw. A sub-genus of Malleus. Lardn. Cyclop. Malac. p. 886. Gray states it to be only a distorted specimen of Vulsella, Syn. B. M. p. 145.
RENIFORM. (Ren, a kidney;forma, shape.) Shaped like a kidney.Ex.The aperture of Ampullaria, fig. 318.
RENULINA. Lam. A genus of microscopic Foraminifera.
REOPHAX. Montf. A genus of microscopic Orthocerata, Bl.
REPENT. (Repens, creeping.) A term applied to those shells, which, being attached by the whole length of their shell, give the idea of creeping or crawling.Ex.Vermilia, fig. 7.
RETICULATED. (Reticulatus.) Resembling net-work.
RETIFERA. Bl. The first family of the order Cervicobranchiata, Bl. containing the genus Patella.
REVERSED orSinistral Shells, are those in which the aperture is on the left side of the shell, while it is held with the mouth downwards, and towards the observer.Ex.Balea, fig. 296. Attached bivalves are said to be reversed, when the left valve is free, instead of the right; a circumstance which sometimes occurs in Chama and Ostrea.
RHEDA. Humph.Hyalæa, Lam.
RHINOCLAVIS. Sw. A genus of "Cerithinæ," Sw. thus described: "channel curved backwards, in an erect position; inner lip very thick, with a tumid margin; pillar generally with a central plait; operculum ear-shaped; lineatum. En. M. 443, fig. 3, Vertagus. Ib. f. 2, subulatum. Lam. No. 23, fasciatum. Mart. 157, f. 1481. obeliscus, En. Méth. 443, f. 4; aluco, Ib. f. 5, (Aberrant,) semi-granosum. Ib. 443, f. 1, asperum. Mart. 157, f. 1483."
RHINOCURUS. Montf. A genus of microscopic Foraminifera.
RHINODOMUS. Sw. A genus of "Scolyminæ," Sw. thus described: No internalgroove; shell clavate; the spire longer than, or equal with the aperture; the whorls with ridges or longitudinal varices, and rendered hispid by transverse grooves; inner lip wanting; pillar with a terminal fold; aperture striated; outer lip with a basal sinus. R. senticosus, Chem. tab. 193. f. 1864-1866.
RHIZORUS. Montf. A genus described from a microscopic shell, appearing to be a cylindrical Bulla.
RHODOSTOMA. Sw. A sub-genus of "Turbininæ," Sw. p. 344.
RHOMBOIDAL. (ῥομβοειδος,rhomboeidus.) Having a rhombic form, i. e. four-sided; two sides meeting at acute, two at obtuse, angles. Conchologists are not very strict in the application of this term, for, indeed, a perfect rhomboidal figure could not be found among all the testaceous productions of the sea.
RHOMBOIDES. Bl. A genus described as resembling Byssomya in the shell, but differing in the animal.Mytilusrugosus, Gmelin.Hypogæabarbata, Poli.
RHOMBUS. Montf. (ῥομβος,rhombos, a rhomb.) A genus consisting of species ofConus, having a rhomboidal or quadrilateral form and a coronated spire.Ex.Conus nocturnus, fig. 459.
RICINULA. Lam. (Resembling the seed-vessel of theRicinus.)Fam.Purpurifera, Lam. Entomostomata, Bl.—Descr.Sub-ovate, thick, tuberculated; spire short; aperture narrow, terminating anteriorly in a short canal; outer-lip thickened, denticulated within, digitated without; columellar lip spread over a portion of the body whorl, and granulated.—Obs.This interesting genus is composed of some neat little shells allied to Purpura, from which they are distinguished by the finger-like branching of the outer lip, and the granulations of the columella. Fig. 413, R. Horrida.
RIGHT. SeeDextral.
RIMULA. Defr. A genus consisting of a minute species ofEmarginula, Auct. which has a fissure near the margin, but not reaching it. R. Blainvillii, fig. 243.
RIMULINA. D'Orbigny. A genus of microscopic Foraminifera.
RINGICULA. Deshayes. A genus founded on Auricula ringens of Lamarck and several small fossils, resembling in some respects Pedipes of Adanson; they would belong to Tornatella, were it not for the lips being thickened and marginated, fig. 540, A. ringens.
RISSOA. Freminville.Fam.Ellipsostomata, Bl. Melaniana, Lam.—Descr.Oblong, turrited, acuminated; spire long, consisting of numerous whorls; aperture round or oval, pointed posteriorly, dilated anteriorly; outer lip slightly thickened, emarginated, operculum horny.—Obs.The Rissoæ are small white, marine shells, considered by some authors as resembling Melaniæ, but placed by Sowerby near the Scalariæ. They are principally from the shores of the Mediterranean, and are also very abundant on the British shores, as well as the East and West Indian. Fig. 346, R. reticulata.
ROBULUS. Montf. A genus of microscopic Foraminifera.
ROLLUS. Montf. A genus composed ofConusGeographus, Auct. fig. 462, and other species, rather cylindrical in form, and having a coronated spire.
ROSALINA. D'Orb. A genus of microscopic Foraminifera.
ROSTELLARIA. (Fromrostrum, a beak.)Fam.Alatæ, Lam. Siphonostomata, Bl.—Descr.Turrited, fusiform, thick, smooth or ribbed; aperture oval, terminating anteriorly in a long canal, posteriorly in a channel running up the spire; outer lip dilated, thickened, sometimes digitated, running up all or part of the spire, with a sinus near the anterior canal; inner lip smooth, spread over part of the body whorl and of the spire. The Red Sea and the Indian Ocean produce the few known species of this genus.—Obs.Hippochrenesis the name given by De Montfort, to those fossil species which have the outer lip simple and very much dilated. R. curvirostrum, fig. 412.Aporrhaisis a name given to another proposed genus, composed of Rostellaria pes-pelecani, Auct. fig. 404. and similar species.
ROSTRATED. (Fromrostrum, a beak.) Having one or more protruding points, as Tellina rostrata.
ROTALIA. Lam. A genus of microscopic Foraminifera. The same as Rotalites of De Montfort.
ROTELLA. Lam. (A little wheel.)Fam.Turbinacea, Lam.—Descr.Orbicular, generally smooth, shining; spire conical, depressed, short; aperture subtrigonal; outer lip thin, angulated near the centre; inner lip spread over the surface of the whorls, forming a thickened disc. Operculum horny, orbicular, spiral, with numerous whorls.—Obs.The pretty little shells thus described are found in seas of tropical climates. They are distinguished from other genera of the family by their lenticular form and the orbicular callosity of the under surface. Fig. 357, R. vestiaria.
RUDISTES. Lam. A family of the order Conchifera Monomyaria, Lam. the shells of which are described as irregular, very inequivalve, without distinct umbones; the ligament, hinge and animal entirely unknown. The shells contained in this family may be thus distinguished.
1.Calceola.Large valve conical; attached by a flat space between the umbones, which form the extremities of the shell. Fig. 194.2.Hippurites.Large valve cylindrical, with two internal lobes or varices. Fig. 198.3.Sphærulites.Large valve attached, includingRadiolites. Birostrites is proved to be the cast of a Sphærulites. Fig. 193, 196.4.Hipponyx.Flat valve attached, upper valve conical. Fig. 199, 200.
1.Calceola.Large valve conical; attached by a flat space between the umbones, which form the extremities of the shell. Fig. 194.
2.Hippurites.Large valve cylindrical, with two internal lobes or varices. Fig. 198.
3.Sphærulites.Large valve attached, includingRadiolites. Birostrites is proved to be the cast of a Sphærulites. Fig. 193, 196.
4.Hipponyx.Flat valve attached, upper valve conical. Fig. 199, 200.
RUDISTES. Bl. The second order of the class Acephalophora, Bl. containing the genera Sphærulites, Crania, Hippurites, Radiolites, Birostrites and Calceola.RUDOLPHUS. Lam.Monoceros, Auct.RUFOUS. Reddish brown.RUGOSE. Rough, rugged.RUPELLARIA. Fl. de Belvue. An unfigured shell placed by De Blainville in a division of the genus Venerirupis.RUPICOLA. Fl. de Belvue. A shell described by De Blainville as an equivalve, terebrating species ofAnatina. A. rupicola, Lam.SABINEA. A genus of shells resembling small species ofLittorina, as L. Ulvæ, &c. of our shores.SADDLE OYSTER.PlacunaSella, so called on account of a resemblance in shape to a saddle; the part near the umbones being flat, and the ventral margins being turned up in a sort of fluting or peak.SAGITTA. (An arrow.) An ancient name for Belemnites.SALIENT. (Saliens.) Jutting out, prominent.SALPACEA. Bl. The second family of the order Heterobranchiata, Bl. containing no genera of shells.SANDALINA. Schum.Crepidulina, Lam. A genus of microscopic Foraminifera.SANGUINOLARIA. Lam. (Sanguis, blood.)Fam.Nymphacea, Lam. Pyloridea, Bl.—Descr.Equivalve, inequilateral, transverse, sub-ovate, rounded anteriorly, sub-rostrate posteriorly, compressed, thin, covered with a shining epidermis, gaping at the sides; hinge with two cardinal teeth in each valve, and an external ligament supported upon a prominent fulcrum; muscular impressions two in each valve, lateral, irregular, palleal impressions with a large sinus.—Obs.This description is made to exclude some of Lamarck's species of Sanguinolaria, such as S. occidens, S. rugosa, which are Psammobiæ; and to include others which he has left out. The Sanguinolariæ are sub-rostrated posteriorly, while the Psammobiæ are sub-quadrate and have a posterior angle. Fig. 98, S. rosea. Sandy shores of tropical climates.SARACENARIA. Defr. A genus of microscopic Foraminifera.SAVIGNIUM. Leach. A genus of Sessile Cirripedes, described as composed of four valves soldered together, and a convex bivalve operculum; the ventral and posterior valve on each side being soldered together, in other respects resemblingPyrgoma. Fig. 30.SAXICAVA. Fl. de Belvue. Journ. de Ph. an. 10. (Saxum, a stone;cava, a hollow.)Fam.Lithophagidæ, Lam. Pyloridea, Bl.—Descr.Transverse, irregular, generally oblong, inequilateral, sub-equivalve, gaping anteriorly; ligament external; muscular impressions two, lateral; palleal impression interrupted, not sinuated; hinge, when young with sometimes two or three minute, obtuse, generally indistinct, cardinal teeth; which become obsolete when full grown.—Obs.Several genera have been founded only upon the difference between the young and old shell of the same species of this genus. The Saxicavæ are found in the little hollows of rocks; in cavities on the backs of oysters, of roots of sea-weeds, &c. in northern and temperate climates. S. rugosa, fig. 94.SCABRICULA. Sw. A sub-genus of Mitræ, consisting of species which have a roughened external surface, &c. Sw. Malac. p. 319.SCABROUS. Rough.SCALA. Klein.Scalaria, Auct.SCALARIA. Auct.Fam.Scalariana, Lam. Cricostomata, Bl.—Descr.Turrited, oval or oblong; spire long, composed of rounded, sometimes separate whorls, surrounded by regular concentric ribs; aperture oval, peristome reflected continuous, entire.—Obs.The typical species of this genus, commonly called the Wentletrap, (S. pretiosa) is celebrated for the beautiful appearance caused by the numerous ribs encircling the whorls, and formerly produced an immense price in the market. It is brought from China. There are many smaller species, some of which are equally elegant. Fig. 351, S. Pallasii, Kiener.SCALARIANA. Lam. A family belonging to the first section of the order Trachelipoda, Lam. The shells belonging to it are described as having the inner and outer lips continuous, without a canal, emargination, or other division. In this respect the family is stated to differ from the Turbinacea, and is therefore separated. The genera may be distinguished as follows:—
RUDISTES. Bl. The second order of the class Acephalophora, Bl. containing the genera Sphærulites, Crania, Hippurites, Radiolites, Birostrites and Calceola.
RUDOLPHUS. Lam.Monoceros, Auct.
RUFOUS. Reddish brown.
RUGOSE. Rough, rugged.
RUPELLARIA. Fl. de Belvue. An unfigured shell placed by De Blainville in a division of the genus Venerirupis.
RUPICOLA. Fl. de Belvue. A shell described by De Blainville as an equivalve, terebrating species ofAnatina. A. rupicola, Lam.
SABINEA. A genus of shells resembling small species ofLittorina, as L. Ulvæ, &c. of our shores.
SADDLE OYSTER.PlacunaSella, so called on account of a resemblance in shape to a saddle; the part near the umbones being flat, and the ventral margins being turned up in a sort of fluting or peak.
SAGITTA. (An arrow.) An ancient name for Belemnites.
SALIENT. (Saliens.) Jutting out, prominent.
SALPACEA. Bl. The second family of the order Heterobranchiata, Bl. containing no genera of shells.
SANDALINA. Schum.Crepidulina, Lam. A genus of microscopic Foraminifera.
SANGUINOLARIA. Lam. (Sanguis, blood.)Fam.Nymphacea, Lam. Pyloridea, Bl.—Descr.Equivalve, inequilateral, transverse, sub-ovate, rounded anteriorly, sub-rostrate posteriorly, compressed, thin, covered with a shining epidermis, gaping at the sides; hinge with two cardinal teeth in each valve, and an external ligament supported upon a prominent fulcrum; muscular impressions two in each valve, lateral, irregular, palleal impressions with a large sinus.—Obs.This description is made to exclude some of Lamarck's species of Sanguinolaria, such as S. occidens, S. rugosa, which are Psammobiæ; and to include others which he has left out. The Sanguinolariæ are sub-rostrated posteriorly, while the Psammobiæ are sub-quadrate and have a posterior angle. Fig. 98, S. rosea. Sandy shores of tropical climates.
SARACENARIA. Defr. A genus of microscopic Foraminifera.
SAVIGNIUM. Leach. A genus of Sessile Cirripedes, described as composed of four valves soldered together, and a convex bivalve operculum; the ventral and posterior valve on each side being soldered together, in other respects resemblingPyrgoma. Fig. 30.
SAXICAVA. Fl. de Belvue. Journ. de Ph. an. 10. (Saxum, a stone;cava, a hollow.)Fam.Lithophagidæ, Lam. Pyloridea, Bl.—Descr.Transverse, irregular, generally oblong, inequilateral, sub-equivalve, gaping anteriorly; ligament external; muscular impressions two, lateral; palleal impression interrupted, not sinuated; hinge, when young with sometimes two or three minute, obtuse, generally indistinct, cardinal teeth; which become obsolete when full grown.—Obs.Several genera have been founded only upon the difference between the young and old shell of the same species of this genus. The Saxicavæ are found in the little hollows of rocks; in cavities on the backs of oysters, of roots of sea-weeds, &c. in northern and temperate climates. S. rugosa, fig. 94.
SCABRICULA. Sw. A sub-genus of Mitræ, consisting of species which have a roughened external surface, &c. Sw. Malac. p. 319.
SCABROUS. Rough.
SCALA. Klein.Scalaria, Auct.
SCALARIA. Auct.Fam.Scalariana, Lam. Cricostomata, Bl.—Descr.Turrited, oval or oblong; spire long, composed of rounded, sometimes separate whorls, surrounded by regular concentric ribs; aperture oval, peristome reflected continuous, entire.—Obs.The typical species of this genus, commonly called the Wentletrap, (S. pretiosa) is celebrated for the beautiful appearance caused by the numerous ribs encircling the whorls, and formerly produced an immense price in the market. It is brought from China. There are many smaller species, some of which are equally elegant. Fig. 351, S. Pallasii, Kiener.
SCALARIANA. Lam. A family belonging to the first section of the order Trachelipoda, Lam. The shells belonging to it are described as having the inner and outer lips continuous, without a canal, emargination, or other division. In this respect the family is stated to differ from the Turbinacea, and is therefore separated. The genera may be distinguished as follows:—
1.Vermetus.Irregularly twisted, like Serpula. Fig. 345.2.Eulima.Pyramidal; apex contorted; includingBonellia. Fig. 347, 348.3.Rissoa.Pyramidal, straight, consisting of few whorls. Fig. 346.4.Scalaria.With external varices. Fig. 351.5.Cirrus.Trochiform. Fig. 349.6.Enomphalus.Orbicular. Fig. 350.7.Delphinula.Few whorls, rapidly increasing. Fig. 352.
1.Vermetus.Irregularly twisted, like Serpula. Fig. 345.
2.Eulima.Pyramidal; apex contorted; includingBonellia. Fig. 347, 348.
3.Rissoa.Pyramidal, straight, consisting of few whorls. Fig. 346.
4.Scalaria.With external varices. Fig. 351.
5.Cirrus.Trochiform. Fig. 349.
6.Enomphalus.Orbicular. Fig. 350.
7.Delphinula.Few whorls, rapidly increasing. Fig. 352.