GONIATITES. De Haan. A genus composed of species of Ammonites, Auct. in which the last whorl covers the spire and the sinuations of the septa are angulated. Fig. 480, G. striatus.GONIDOMUS. Sw. A sub-genus of Geotrochus, Sw.Pupapagodus, Auct. Sw. p. 332.GONIOSTOMA. Sw. A sub-genus of Bulimus, thus described, "spire elongated, of few whorls; aperture contracted at each end; lips margined; the pillar curving inwards; the base slightly notched. G. erubescens,Sw.Zool. Journ. i. pl. 5, f. 2." Sw. p. 335.GONIOSTOMATÆ. Bl. A family belonging to the order Asiphonibranchiata, Bl. containing the genera Solarium and Trochus.GONOSPIRA. Sw. A sub-genus of Pupa, thus described, "spire perfectly cylindrical, of equal thickness, the tip obtuse, with the whorls large; aperture oval; lips thickened; pillar with or without a plait. G. polanga,Desh.Lesson, Voy. pl. 8, f. 8." Sw. p. 333.GRANULATED. (Granum, a grain.) Covered with minute grains, rough. The granulated lip of Oniscia, (fig. 409) will serve as an example.GRATELOUPIA. Moulins.Fam.Nymphacea, Lam.—Descr.Equivalve, inequilateral, sub-cuneiform, rounded anteriorly, sub-rostrated posteriorly; hinge with three cardinal teeth, a series of five or six irregular, small, diverging teeth behind the umbones, and one lateral anterior tooth in each valve; ligament external; muscular impressions two; palleal impression sinuated posteriorly.—Obs.This genus (Donax irregularis, Bast.) is only known in a fossil state. Fig. 102, G. Moulinsii.GRYPHÆA. Lam. (From Gryps, a griffin.)Fam.Ostracea, Lam.—Descr.Inequivalve, free; lower valve large, concave; with the umbo prominent, incurved; upper valve small, flat, opercular; hinge toothless, with a curved, depressed area; one muscular impression.—Obs. These shells, which approach the Oysters, are of a more regular form, and are remarkable for the curved, produced beak of the lower valve. They are only known in a fossil state, belonging to the more ancient strata. Fig. 182, G. incurva. The recent species mentioned by Lamarck is not a true Gryphæa.GYMNOLEPAS. A generic name used by De Blainville to includeOtionandCineras, Leach.GYMNOSOMATA. Bl. The second family of the order Aporobranchiata, in the system of De Blainville. The animals belonging to this family are destitute of shells.GYPIDEA. Dalman. A genus of Brachiopoda, thus described, "Larger valve with the umbo rostrated, remote from the hinge; with the canal large, deltoid; bilocular within."Pentamerus, Sow. Fig. 210. 211, G. Conchidium, copied from Dalman.GYROGONA. Lam. A genus of microscopic Foraminifera.GYROIDINA. D'Orb. A genus of microscopic Foraminifera.HALIOTIDÆ. Sw. A sub-genus of Calyptræa.Calyptræadilatata. Sowerby's Genera of Shells, fig. 9.HALIOTIS. Auct. (αλς,als, sea;ους,ωτος,otos, ear.)Fam.Macrostomata, Lam. Otides, Bl.—Descr.Auriform, broad, depressed, pearly within, rough, costated, tuberculated without; spire short, flat, consisting of one or two whorls; aperture wide; ovate; columella laminar, flat,oblique; a spiral series of perforations running along the dorsal margin.—Obs.The splendid shells belonging to this genus are remarkable for the pearly iridescence of the inner surface, and the row of holes following the course of the spire. The soft parts are eaten in Guernsey and Jersey, and reckoned delicious. They belong to temperate and tropical climates. Fig. 338, H. rubra. 339, Padollus, Montf.HALIOTOID. (Haliotisandειδος,eidos, form.) Ear-shaped.HAMIFORM. (Hamus, a hook.) Curved at the extremity.HAMITES. Parkinson. (Hamus, a hook.)Fam.Ammonacea, Lam.—Descr.Elongated, cylindrical, chambered, recurved at the smaller extremity, annulated; septa lobed and sinuated.—Obs. This remarkable fossil from the Baculite limestone in Normandy, differs from Baculites in being curved at one extremity, a circumstance from which its name is derived. Some small species are found in Chalk-Marle, Folkstone. Fig. 484*. H. cylindricus.HARPA. Brug. (Harpa, a harp.)Fam.Purpurifera, Lam. Entomostomata, Bl.—Descr.Oval, ventricose, longitudinally and regularly costated; spire short, with rounded, dome-like whorls; aperture wide, emarginated; outer lip thickened, reflected, composing the last costa or rib; inner lip polished, spread over part of the body whorl, terminating in a point.—Obs.This beautiful genus of shells is so clearly defined by the regular, longitudinal ribs that adorn the external surface, suggesting the idea of a stringed instrument, that there is no danger of confounding it with any other. H. multicostata, (Buccinum costatum, Linn.) and H. ventricosa, are among the most elegant of the testaceous productions of the sea both in form and colouring; the former is rare. The recent species are not numerous, they inhabit the Indian Ocean. A fossil species occurs at Grignon, near Paris. Fig. 419, H. ventricosa.HARPAX. Parkinson. Part ofPlicatula, Auct.HARPULA. Sw. A group of shells separated fromVoluta, Auct. thus described, "shell generally tuberculated or longitudinally ribbed; apex of the spire papillary, smooth, and in general distorted; pillar with numerous distinct plaits; the upper, small and slender, the lower, thickest and shortest."—Type, H. Vexillum. (Voluta, Auct.)HAUSTATOR. Montf. A genus proposed to include those species ofTurritella, Auct. which have angulated whorls.HAUSTELLARIA. Sw. A sub-genus of Murex, consisting of species with long canal and no spines. Murex Haustellum, fig. 396.HAUSTRUM. Humph.Purpura, Lamarck.HELCION. Montfort. A genus composed of species of Patella, which have the apex distinctly and prominently bent forwards.Ex.P. pellucida, fig. 230.HELENIS. Montf. A genus of microscopic Foraminifera.HELICELLA. Fer. One of the sub-genera into which De Ferussac has divided the genus Helix, consisting of depressed species with large umbilicus, such as Helix Algira, fig. 279. Gonites Montf.HELICIFORM. Shaped like shells of the genus Helix.HELICIGONA. One of De Ferussac's sub-genera of the genusHelix, consisting of angulated species, such as Carocolla Lamarckii, fig. 277.HELICINA. Lam.Fam.Colimacea, Lam. Ellipsostomata, Bl.—Descr.Globose, compressed, or angulated, generally light and thin; aperture trigonal or semilunar; outer lip thickened and generally more or less reflected; inner lip spread over the body whorl, frequently callous near the columella, which is short, and terminates in a notch, angle, or slight callosity.—Obs.This genus of land shells, distinguished from the genus Helix, by having an operculum and a thickened columellar lip, differs also from Cyclostoma in having the aperture semicircular or angular, the peritreme discontinuous and the operculum concentric. These shells are generally small in size, and simple in form. Lamarck describes only three or four species. Mr. Gray described some others in the Zoological Journal, and in a work shortly to be published by the author, a monograph of the genus will contain descriptions and figures of at least 60 distinct species; some of which have been lately brought to this country by Mr. Cuming from the Philippine Islands. They mostly belong to tropical climates.HELICITES. Bl. Part of the genusNummulites, Lam.RotalitesandEgeon, Montf.HELICOGENA. Fer. A sub-genus of Helix, consisting of species, which, like the common garden snail, fig. 268, are globose and simple in form.HELICOLIMAX. Fer.Vitrina, Drap. H. Pellucida, fig. 263.HELICOPHANTA. Fer. A sub-genus of Helix, consisting of ear-shaped species with large open apertures.HELICOSTYLA. Fer. A sub-genus of Helix, consisting of species with numerous whorls, as H. Epistylium, fig. 281.HELISOMA. Sw. A sub-genus of Planorbis. Sw. p. 337.HELIX. Auct.Fam.Colimacea, Lam.—Descr.Orbicular, light, generally globular; spire short, last whorl ventricose, aperture oblique, peritreme reflected, interrupted by the most prominent part of the body whorl; columella confluent with the outer lip, and contiguous to the axis of the shell. No operculum; a thin epidermis.—Obs.The land shells composing this genus are found in all parts of the world; the common snail, H. Aspersa, is well known as a destructive animal in our gardens. The genera Helix, Achatina, Bulinus, Clausilia, Anostoma, &c., have been united under one generic name by De Ferussac, and again divided under the following sub-generic names, each of which we shall illustrate by a figure.Genus Helix:Sub-genus1,Helicophanta, consisting of species with large apertures, like Vitrina; Helix brevipes.S. gen. 2,Cochlohydra, Succinea Amphibia, Drap.S. gen. 3,Helicogena, consisting of the common species with the last whorl large; Helix Hæmastoma, H. Contusa, (Streptaxis, Gray,) H. Aspersa.S. gen. 4,Helicodonta, consisting of species with teeth or folds on the columella; Polydonta, Montf. Anostoma, Helix Nux-denticulata.S. gen. 5,Helicigona, Carocolla, Geotrochus.S. gen. 6,Helicella, consisting of depressed species with a large umbilicus; H. Citrina (Naninia, Gray.)S. gen. 7,Helicostyla, consisting of species with a simple aperture, like the Helicogenæ, but with the whorls increasing very gradually; H. epistylium.S. gen. 8,Cochlostyla, Bulinus.S. gen. 9,Cochlitoma, Achatina.S. gen. 10,Cochlicopa, Polyphemus Glans.S. gen. 11,Cochlicella, Bulinus decollatus.S. gen. 12,Cochlogena, Azeca tridens.S. gen. 13,Cochlodonta, Pupa Uva.S. gen. 14,Cochlodina, Clausilia macascarensis, Balea fragilis. The last three sub-genera are included in the genus Odostomia of Fleming. We give an example of each of these sub-divisions, for the sake of presenting the reader with the principal variations to which the genus is subject. The established genera will be characterized in their places. Fig. 254 to 281.HELIXARION. Fer.Vitrina, Drap. Differing from Helicolimax in the structure of the animal. Fig. 262.HEMICARDIUM. Cuv. (ἡμισυς,hemisus, half,ΚαÏδια,cardia, heart.)CardiumHemicardium, fig. 123**, and several similar species.HEMICYCLA. Sw. A sub-genus of Helix.HEMICYCLONOSTA—seeCardilia.HEMICYCLOSTOMATA. Bl. The fourth family of Asiphonibranchiata, Bl. described as "more or less globular, thick, flattened on the under side; spire very short; aperture large, semilunar, entire; its outer edge hollowed; its inner or columellar edge straight, sharp and septiform." This family answers to the genusNeritaof Linnæus, and to the family Neritacea of Lamarck. It contains the genera Natica, Nerita, Neritina, and Navicella.HEMIMACTRA. Sw. A sub-genus of Mactra, thus described: "General form ofMactra; but the cardinal teeth entirely wanting; cartilage internal, central, in a large triangular cavity; lateral teeth 2/1, distinct, lateral, striated: connected to theGlycimeri. H. gigantea,Lam.v. 472. No. 1. grandis,Sw.Sp. Nov." Sw. p. 369.HEMIMITRA. Sw. A sub-genus of Paludomus, Sw. (Melanianæ.)HEMIODON. Sw. A sub-genus of Anodon, described as having "Tubercles or undulations on the hinge margin. H. undulatus, purpurascens and areolata."HEMISINUS. Sw. A sub-genus of Melania, thus described: "General shape ofMelania; but the base of the aperture is contracted and emarginate; outer lip crenated. H. lineolata, Griff. Cuv. xii. pl. 13. fig. 4."HEMITOMA. Sw. A sub-genus of Emarginula, thus described: "Patelliform; the fissure not cut through the shell, but merely forming an internal groove. H. tricostata,Sw.Sow. Gen. fig. 6."HEMITROCHUS. Sw. A sub-genus of Geotrochus, Sw. H. hæmastoma. Sw. p. 331.HEPTALASMIS. Leach. (Ἡπτα,hepta, seven;ελασμα,elasma, plate) A small shell resembling Pentelasmis, from which it differs in the number of valves, being composed of seven valves according to Leach, and of eight according to Gray, who counts the dorsal valve, which is jointed, astwo, and names his genus Octolasmis. Fig. 41, H. Warwickii.HERCOLES. Montf. A microscope shell, appearing from De Montfort's figure to resembleTrochusImperialisin shape.HERION. Montf.Lenticulina, Bl. Microscopic.HERMAPHRODITA. Bl. The third sub-class of Paracephalophora, Bl. divided into, Sect. 1,symmetrical, containing the orders Cirrobranchiata and Cervicobranchiata; Sect. 2,non-symmetrical, order, Scutibranchiata.HERMES. Montf. A genus composed ofConusNussatella, Auct. and other elongated, cylindrical, striated species. Fig. 460.HETEROBRANCHIATA. Bl. The fourth order of the class Acephalophora, Bl. containing no testaceous mollusca.HETEROPODA. Lam. The fifth order of the class Mollusca, Lam. This order contains but one genus of shells, viz. Carinaria, fig. 488.HETEROSTEGINA. D'Orb. A genus of microscopic Foraminifera.HIATELLA. Daud. Fam. Lithophagidæ, Lam. A genus composed of species of Saxicava, Auct. which have sharp, angulated, posterior ridges, a circumstance which occurs to many species in a young state, which afterwards become rounded off. Fig. 95, Hiatella biaperta.HIATULA. Sw. A genus proposed to include those species of Oliva, Auct. which have widened apertures.Ex.O. Subulata, fig. 458.HIBOLITHES. Montf. A genus composed of species of Belemnites, Auct. which are swelled towards the apex, and contracted near the centre. B. Hastatus, Auct. fig. 468.HIMANTOPODA. Schum.Malleus, Auct.HINGE. The edge of the bivalve shells near the umbones, including the teeth and ligament.HINNITES. Defr. A generic name proposed forPecten Pusio, Auct. remarkable for the irregularity of the outer surface, which would almost lead to the belief of its being an attached shell. Fig. 173, H. Pusio.HIPPAGUS. Lea. (Horse boat.) A minute fossil shell, resembling Isocardia in form, but destitute of hinge teeth. H. Isocardioides, fig. 128.HIPPOCHRENES. Montf. Species ofRostellaria, Auct. with the outer lip spread. Fig. 403. R. Columbaria.HIPPONYX. (Ἱππος,hippos, horse;ονυξ,onyx, nail or hoof.)Fam.Rudistes, Lam.—Descr.Inequivalve, sub-equilateral, rather irregular, destitute of ligament and hinge teeth; lower valve attached, flat, sub-orbicular, with a muscular impression, composed of two lunulate portions, meeting at one extremity, and presenting the form of a horse-shoe; upper valve conical, with the apex inclined backwards, and the muscular impression marginal.—Obs.The earlier naturalists having only met with the upper valve of these shells, placed them among the patelliform univalves; to some of which, particularly Pileopsis, they bear a very strong resemblance. The species of Hipponyx are numerous, and till lately only known in a fossil state. The recent species belong to tropical climates: the fossil species are found in the tertiary beds. Fig. 199, H. Cornucopia.HIPPOPODIUM. Conybeare.Fam.Cardiacea, Lam.—Descr.Equivalve, obliquely transverse, heavy, deep, inequilateral, umbones incurved; ventral margin sinuated, so as to give a bilobed appearance to the shell; hinge incrassated, with one rugged oblique tooth.—Obs.These fossils are found in the upper beds of Lias. Fig. 129, H. Ponderosum.HIPPOPUS. Lam. (Ἱππος, hippus;πους,pous, foot.)Fam.Tridacnacea, Lam.—Descr.Equivalve, inequilateral, regular, subquadrate; lunule closed, flat, with crenulated edges; ventral margin deeply undulated; external surface fluted, with radiating ribs, which are transversely fringed with rows of tubular spines; hinge margin thick, with two long, compressed posterior lateral teeth in one valve, three in the other; ligament marginal, external.—Obs.The shell thus described is rightly separated from Tridacna, on account of the anterior dorsal margins being closed; whereas in Tridacna there is a wide hiatus. Only one species of this genus is known, which receives its name from its resemblance in form to a horse's foot, when held with the flat anterior dorsal margin downwards. Few shells are found to concentrate so many beauties as the Hippopus Maculatus, commonly called the Bear's-paw-clam; the delicate whiteness of the interior, the undulating edge, the radiated fluted columns, adorned at intervals by crisped fringes, and the richness of the variegated colouring, are such as to secure the admiration of the most superficial observer. From the Indian Archipelago. Fig. 156, H. Maculatus.HIPPURITES. Montf.Fam.Orthocerata, Lam. Rudistes, Bl.—Descr.Tabular, rude, irregular, attached; lower valve cylindrical, more or less lengthened, apparently divided into sections by septa (considered by some authors as merely projecting layers of growth) having one or two lateral tubes within; upper valve round, flat, fixed on the aperture of the tubular valve like an operculum.—Obs.This genus is known only in a fossil state, and but very imperfectly. Lamarck places it among his chambered Cephalopoda, &c. De Blainville, considering it a true Bivalve, enumerates it among his Rudistes. Cretaceous group. Fig. 198, H. Cornucopia.HORTOLUS. Montf.Spirolina, Lam. Microscopic.HYALÆA. Auct. (Hyalus, glass.)Fam.Pteropoda, Lam. Thecosomata, Bl.—Descr.Globose, glassy, transparent, with a triangular opening at the upper part where the dorsal portion advances beyond the ventral; ventral portion vaulted; dorsal more flat; lower extremity tridentate.—Obs.The singular structures composing this genus were formerly taken for bivalves, and named Anomia Tricuspidata, &c. They are now known to belong to the class of molluscous animals, called Pteropoda, from the wing-shaped organs of locomotion. A species of Hyalæa occurs in Sicily in a fossil state. Recent species are found in the Mediterranean, Atlantic, and Indian Oceans. Fig. 226, H. Tridentata.HYALINA, Studer.Vitrina, Drap.HYALINE. (Hyalus, glass.) Glassy, thin, transparent—Ex.Carinaria Mediterranea, fig. 488.HYDROBRANCHIATA. Bl. The first section of the order Gasteropoda, Lam. containing Molluscs which breathe water only; divided into the families Tritoniana, Phyllidiana, Semi-phyllidiana, Calyptracea, Bullæana, and Aplysiana.HYGROMANES. Fer. A sub-division of Helix, containing H. limbata, Auct. &c. Gray's Turton, p. 143.HYRIA. Lam. A genus composed of species of Nayades, distinguished by their alated dorsal margins, and lamellated lateral teeth. South America.Hyriacorrugata, fig. 143, Hyria Syrmatophora, fig. 144.HYRIDELLA. Sw. A genus of "Hyrianæ," Sw. described as differing fromHyria, Auct. in having a cardinal as well as a lateral tooth in each valve. Sw. p. 380.HISTRIX. Humph.Ricinula, Auct.JANERA. Schum. A genus composed of species of Pecten, Auct. having oblique plicæ or calli on each side of the ligamentary pit.Ex.P. plica, fig. 172. Decadopecten, Rüppell.JANTHINA. Auct. (Janthum, a violet.)Fam.Neritacea, Lam. Oxystomata, Bl.—Descr.Sub-globose, thin, fragile; spire short, consisting of few whorls; aperture angulated, at the anterior junction of the inner and outer lips; columella tortuous, contiguous to the axis; outer lip thin, sinuated in the centre.—Obs.The shells composing this genus are celebrated for their beautiful purple colour. The animal possesses a small vesicular process, which keeps it floating on the surface of the water; it exudes a purple secretion when irritated. It is occasionally floated on to the shores of most temperate and tropical countries. Fig. 333, J. Fragilis.JATARONUS. Adanson.Chama, Auct.IBERUS. Montf.Carocolla, Lam.IBLA. Leach.Fam.Pedunculated Cirripedes, Lam.—Descr.Four valves, posterior pair elongated, anterior pair short, triangular; pedicle cylindrical, contracted at the base, hairy.—Obs.I. Cuveriana (fig. 40) is brought from Kangaroo Island.ICTHYOSARCOLITES. Desmarest.Fam.Ammonacea, Lam.—Descr.Chambered, slightly arcuate, laterally compressed; septa simple, leaving triangular articulations imbricated like the thick muscles of a fish.JESITES. Montf. A minute fossil resemblingGaleolaria.ILOTES. Montf.Orbiculina, Bl. A genus of microscopic Foraminifera.IMBRICARIA. Schum.Conohelix, Sw.IMBRICATED. (Imbrex, a tile.) A shell is said to be imbricated when the superficial laminæ are arranged over each other in the manner of tiles.IMPERATOR. Montf. A genus composed of species of the genusTrochus, Auct. with whorls angulated and stellated, having an umbilicus.Ex.T. Imperialis. Some of the shells named Imperator in the British Museum belong to the genus Calcar, Montf. having no umbilicus.IMPRESSION. SeeMuscular Impression.INCRASSATED. (Crassus, thick.) Thickened, as the hinge of Glycimeris, fig. 67.INCURVED. Turned inwards or bent forwards. Applied to symmetrical shells, when the point of the apex turns towards the anterior extremity, as in Patella. The apex of a shell is said to be incurved when it is bent inwards, but not sufficiently so to be described as spiral.Ex.Ammonoceras, Lam. fig. 477.INDENTED. (In, in;dens, a tooth.) Exactly the reverse ofDentated; meaning a series of small cavities, such as might be produced by the entrance of teeth. The cast of a dentated surface would be indented.INEQUILATERAL. (Æquus, equal;latus, a side.) A term applied to a bivalve shell when its extent on one side of the umbones is greater than that on the other. When the sides are nearly equal, the termsub-equilateralis used.INEQUIVALVE. (in;æquus, equal;valva, valve.) The two principal valves differing from each other in diameter or convexity.INFERIOR VALVE is that which is attached to sub-marine bodies. Only applied to attached bivalves.INFEROBRANCHIATA. Bl. The fourth family of the second section of Paracephalophora Monoica, Bl. containing no testaceous mollusca.INFLATED. Swelled, as Bulla, fig. 250, 252. This term can only be applied to rotund shells of a light, thin texture. In other cases we should use the wordVentricose.INFLECTED. Turned inwards. This term is applied to the outer lip of a spiral shell when it turns towards the body whorl. This is the case in Cypræa, fig. 446. SeeReflected.INFUNDIBULUM. Montf. (A funnel.) A genus formed of those species ofCalyptræa, Lam. which, having a spiral septum, so nearly resemble Trochus that some authors have placed them in that genus. One species named Patella Trochiformis. Recent from South America, fossil from the tertiary beds. Fig. 237, 238, Calyptræa (Infundibulum) Pileus.INNER LIP. That edge of the aperture of an univalve shell which is near to the imaginary axis, as distinguished from the outer lip, or that which is on the opposite side.INOCERAMUS. Sow.Fam.Malleacea, Lam. Margaritacea, Bl.—Descr.Thick, inequivalve, sub-equilateral, triangular, deep, with the umbones incurved; hinge formed of a series of transverse grooves.—Obs.The larger valves of these fossil shells resemble the larger valve of Gryphæa; but the hinge is quite distinct. The species described in Mineral Conchology are found in the blue marl, at Folkstone, and in the chalk. I. Lamarckii, (Catillus, Brong.) fig. 167.INTERNAL CAST. The mould of a fossil shell, composed of matter which entered the shell in a soft state, and has subsequently hardened, when, the shell dropping off, the hardened substance which filled it is left to represent its internal form.INTERNAL LIGAMENT. A term used by some conchological writers signifying that the ligament of a bivalve shell is placed within the closed part of the hinge, so as not to be seen when the valves are shut. But the substance, formerly called the internal ligament, is now distinguished from the true ligament both in structure and use; and is now more properly called the cartilage, so that when the ligament is said to be internal, it must be understood that the internal cartilage is unaccompanied by any ligament properly so called, and when a shell is described as having two ligaments, as in the case of Amphidesma, it means that the two substances are so far removed from each other in the hinge that they are no longer confounded together.INTERNAL SHELL is one which is enclosed in the soft parts of the animal, as a bone is enclosed in the flesh of a human body. The Limax, or common garden slug, which has a testaceous shield beneath its mantle, is an instance of this.IO. Lea. A genus composed of several species of fresh-water shells which are considered as differing from Melaniæ in having the anterior termination of the aperture produced into a point in some degree resembling the caudal canals of shells belonging to the family of Canalifera, which are marine. Io fusiformis and spinosus are described and figured in Lea's work on the genus Unio.JODAMIA. Defr. A genus resembling Birostrites, except that in Jodamia one valve overwraps the other, while in Birostrites the circumference of the valves is equal.IPHIGENIA. Gray. A sub-genus of Clausilia, C. biplicata, &c. Auct. Gray's Turton, p. 214.IRIDEA. Sw. A genus of "Hyrianæ," Sw. thus described:—"Oblong ovate; bosses small, depressed, sulcated; inner cardinal tooth placed beneath the outer. I. granosa,Lam.En. Méth. 248. fig. 9."IRIDINA. Auct. A genus belonging to the Nayades, and resembling theAnodontæ, Auct. but its peculiar characteristic is that the hinge lamina is tuberculated or crenulated in its whole length. Sowerby unites all the genera of the family into the genusUnio. Fig. 150, I. Elongata.IRREGULAR SHELLS, are those which, being attached to, or imbedded in other marine bodies, have no constant form, but are modified in shape according to the substances to which they are fixed, as the Chamacea, fig. 153 to 155.IRUS. Oken. ComprehendingPandora,Petricola,Saxicava, &c.ISOCARDIA. Lam. (Ισος,isos, similar;ΚαÏδια,cardia, heart.)Fam.Cardiacea, Lam. Chamacea, Bl.—Descr.Cordiform, regular, equivalve, ventricose, with distant, diverging, involute, free umbones; hinge with two compressed cardinal, and one distant, compressed lateral teeth in each valve; ligament external, bifid, diverging in the direction of the umbones.—Obs.The shells composing this genus are remarkable for the beautiful curvature of the diverging umbones. European and Chinese Seas. Fig. 126, I. Moltkiana.KEEL. A flattened ridge, resembling the keel of a ship. As that on the back of Carinaria vitrea, fig. 488, and those on the whorls of some spiral shells. A shell characterized by a keel or keels is said to be carinated.KELLIA. Turton,MyaSuborbicularis, Montague.LABIS. Oken.Monodonta, Lam.LABIUM, or inner lip,—is used to express that side of the aperture which is nearest to the axis and generally contiguous to the body whorl. The lower part of this, when sufficiently distinct from that part which overwraps the body whorl, is called the Columella.LABRUM, or outer lip,—is the edge of the aperture at the greatest distance from the axis.LACINEA. Humph.Chama, Lam.LACUNA. Turt.Fam.Turbinacea, Lam.—Descr.Globose, thin, covered with a smooth epidermis; spire short, consisting of few rapidly increasing whorls; aperture semilunar, rounded at the extremities; columella oblique, reflected over part of the umbilicus; umbilicus forming a lengthened area behind the columella. Northern shores. Fig 364, L. Pallidula.LAGENULA. Montf. A genus of microscopic Foraminifera.LAMELLATED. (Lamella, a thin plate.) When the layers of which a shell is composed, instead of being compacted into a solid mass, are separated, overlying each other in the manner of tiles, with the edges prominent, the structure is said to be lamellated or foliaceous.LAMELLIBRANCHIATA. Bl. The third order of the class Acephalophora, Bl. consisting of bivalve shells, divided into the families Ostracea, Subostracea, Margaritacea, Mytilacea, Polydontes, Submytilacea, Chamacea, Conchacea, Pylorides, Adesmacea.LAMELLIPEDES. Lam. (Lamella, a thin plate,pes, a foot.) The third section of the order Conchifera Dimyaria, containing bivalves, with the foot of the animal broad and thin; divided into the families Conchacea, Cardiacea, Arcacea, Trigonacea, Nayades. Fig. 111. to 152.LAMPAS. Montf.Lenticulina, Bl. A genus of microscopic Foraminifera.LAMPRODOMA. Sw. A genus of "Olivinæ," Sw. thus described:—"Mitriform; spire produced, conic; resemblingMitrellain shape, but the suture is channelled; the aperture effuse at the base, contracted above; lower half of the pillar with 6 to 7 plaits. Volutella, Zool. Ill. ii. series, pl. 40. f. 1. (fig. 86.)" Sw. p. 321.LAMPROSCAPHA. Sw. A sub-genus of "Anodontinæ," Sw. thus described:—"Shell not winged, elongate, pod-shaped; teeth none; bosses near the anterior extremity. Tropical America only? L. ? elongata.Sw.Zool. Ill. i. 176. ensiforme,Spix.Braz. Test. siliquosa. Braz. Test. pygmæa. Ib." Sw. p. 381.LAMPROSTOMA. Sw. A sub-genus of Canthorbis (Trochus), described at p. 350, Lardn. Cyclop. Malac.LAMPUS. Humph.Terebratula, Lam.LANCEOLATE. Lengthened like a lance.LANISTES. Montf. Reversed species ofAmpullaria, fig. 319.LAPLYSIA. SeeAplysia.LAPLYSIACEA. Lam. (properly Aplysiacea) A family belonging to the first section of the order Gasteropoda, Lam. containing the genera Aplysia and Dolabella. Fig. 254, 255.LARVA. Humph.Fissurella, Lam.LATERAL. (Latus, a side.) The lateral teeth are those which, taking their rise near the umbones, proceed to some distance towards the sides of the shell; as distinguished from the cardinal teeth, which receive their full developement close to the umbones. Lateral muscular impressions are those which are placed at a distance from each other, on the opposite sides of the shell.LATIAXIS. Sw. A genus of "Eburninæ," Sw. corresponding with the genus Trichotropis. Sow. (Sw. Malac. p. 306.)LATIRUS. Montf. A genus composed of species ofFusus, Auct. which have an umbilicus and are turriculated.LAURIA. Gray. A sub-genus ofPupa, containing P. umbilicata, &c. (Gray's Turton, p. 193.)LEGUMINARIA. Schum. A genus composed of species ofSolen, Auct. which have an internal longitudinal bar or rib. Fig. 61. S. Radiatus, Lam.LEILA. Gray? Described as having the hinge edge smooth like Iridina, but having a "sharp siphonal inflexion." (Syn. B. M. p. 142.)LEIODOMUS. Sw. A genus of "Buccininæ," Sw. consisting of Terebra vittata and other similar species. This genus corresponds with Bullia, Gray.LEIOSTOMA. Sw. A genus of "Fusinæ," Sw. thus described, "Equally fusiform," (with Fusus) "but ventricose in the middle; shell entirely smooth, almost polished; inner lip thickened, and vitreous; base of the pillar very straight. Fossil only. (fig. 75.) L. bulbiformis. En. Méth. 428. f. 1."LEMBULUS. Leach. A genus composed of oval species ofNucula, resembling N. margaritacea, fig. 137.LENDIX. Humph.Pupa, Lam.LENGTH. SeeMeasurement.LENTICULAR. (Lens.) Of a circular, convex form, as Pectunculus, fig. 134.LENTICULINA. Lam. A genus of microscopic Foraminifera.—Descr.Lenticular, sub-discoidal, compressed, convolute, symmetrical; aperture notched; chambers few in number; visible on the exterior, radiating from the centre of the disk.LEPADICEA. Bl. The first family of the class Nemantopoda, Bl. This family consists of the same animals which constitute the Pedunculated Cirripedes of Lamarck, and part of the genus Lepas in the system of Linnæus. It contains the genera Gymnolepas, Pentalepas, Polylepas and Litholepas.LEPAS. (Λεπας,lepas, a rock.) The Linnæan name Lepas contains all the Cirripedes or Multivalves, the different kinds of which are not distinguished in the accounts given by early writers of the habits of the animals. (Fig. 14 to 43.) It was formerly applied to the Limpets or Patella. In fact, the ancient definition was "Concha petræ adhærens," and would apply to any shells attached to rocks.LEPTÆNA. Dalman. A genus belonging to the Brachiopoda; and thus described:—"Hinge compressed, rectilinear, frequently exceeding the width of the shell." It forms part of the genus Producta, Sow. Fig. 206, L. depressa.LEPTOCONCHUS. Rüppell. (Λεπτος,leptus, thin;Κογχος,conchos, shell.) This shell resembles a youngMagilusin general appearance, although the animal is said to differ. In the young Magilus also, the inner lip is reflected over the body whorl, which is not the case in Leptoconchus. Red Sea. Fig. 11.LEPTOCONUS. Sw. A sub-genus of Conus, consisting of Conus grandis, amadis, duplicatus, Australis, &c. Sw. p. 312.LEPTOLIMNEA. Sw. A sub-genus of Limnea, described as being nearly cylindrical. Limnea elongata, Sow. Gen. fig. 6.LEPTON. Turton.SolenSquamosus, Montague, and other species described as "flat, nearly orbicular, equivalve, inequilateral, a little open at the sides. Hinge of one valve with a single tooth, and a transverse linear lateral one on each side; of the other valve, with a cavity in the middle and a transverse deeply cloven lateral tooth each side, the segments of which divaricate from the beak." To represent this genus we have figured L. Squamosum in the plates, fig. 62. British.LEPTOSPIRA. Sw. A sub-genus of Bulinus, thus described: "Spire excessively long, sub-cylindrical; body whorl largest; outer lip thickened; aperture oval; no teeth, striata,Sw.Chem. 135. f. 1226. signataSw." Sw. p. 335.LEUCOSTOMA. Sw. A genus of "Achatina," Sw. described as resembling Achatinella, but having a "thick pad" at the top of the "upper lip," and another over the base. L. variegata, Sw. Lardn. Cyclop. Malac. fig. 24. p. 172.LEUCOTUS. Sw. A sub-genus of Natica, described as intermediate between Sigaretus and Lacuna.Sigaretuscancellatus, Lam. (Sw. Malac. p. 346.)LICIUM. Humph.Ovula, Lam. (Ovulum.)LIGAMENT. (FromLigo, to bind.) The true ligament is always external, and serves the purpose of binding the two valves of a shell together externally by the posterior dorsal margins. There is another substance, called by Gray theCartilage, which is elastic and of a condensed fibrous structure, placed within the ligament, either close to it, or at a more interior part of the shell; it is sometimes contained in a pit, formed for its reception, in the centre of the hinge. This substance, being elastic, keeps the valves open, unless drawn together by the counteracting force of the adductor muscles. When conchologists speak of a shell as having the ligament external, the real meaning is that these two substances are so close together as in appearance to constitute one body placed outside the shell so as to be seen when the valves are closed. When two ligaments are spoken of, as in Amphidesma, the meaning is that the cartilage occupies a separate place on the hinge.LIGAMENTIFEROUS. (Ligamentum, a ligament,fero, to bear.) Having or containing the ligament, as the cardinal pit in Mya, fig. 71.LIGULA. Leach. A genus containing the more rounded and less gaping species ofLutraria, Auct. Fig. 77, Lutraria Papyracea.LIGULATE. (Ligula, a slip, a shoe-latchet.) Thin, slender, like a slip, or neck of any thing, as the anterior muscular impression of Lucina, fig. 104.LIGUMIA. Sw. A sub-genus of Unio, thus described:—"Very long and pod-shaped; bosses depressed; cardinal teeth moderate. S. recta. Lam. vi. 1. p. 74." Sw. p. 378.LIGUUS. Montf. A genus containing species ofAchatina, Auct. which have rounded apertures and lengthened spires, differing from hisPolyphemi, which have lengthened apertures. A. virginea, Auct. fig. 286, is the type of this genus.LIMA. Brug. (Lima, a file.)Fam.Pectinides, Lam. Subostracea, Bl.—Descr.Equivalve, inequilateral, compressed, oblique-auriculated, oval, radiately ribbed or striated, imbricated, covered with a light brown epidermis; hinge with a triangular disc between the umbones, divided in the centre by a triangular ligamentary pit without teeth; muscular impression one, sublateral, sub-orbicular.—Obs.The shells thus described are marine, two or three species being found on our coasts, and fossil species occurring in Lias, inferior Oolite, Calcaire-grossiér, &c. They differ from Pecten in having a wide hiatus for the passage of a byssus, by which they are occasionally attached, and also in the triangular disc, which separates the umbones. The animal makes use of the valves of his shell as natatory organs, working them like fins or paddles, and by this means proceeding at a rapid rate through the waters. L. Squamosa, fig. 174.LIMACINA. Cuv. (Limax, a snail.)Fam.Pteropoda, Lam.—Descr.Papyraceous, fragile, planorbicular, sub-carinated, obliquely convolute; spiral side rather prominent, the other side umbilicated; aperture large, entire, not modified, peristome sharp.—Obs.This isSpiratella, Bl. The shell figured as Limacina in Sowerby's Genera, under "pteropoda," is anAtlanta. Our representation of Spiratella Limacinea, fig. 224. is copied from Blainville.LIMACINEA. Lam. A family of the order Gasteropoda, Lam. including the following
GONIATITES. De Haan. A genus composed of species of Ammonites, Auct. in which the last whorl covers the spire and the sinuations of the septa are angulated. Fig. 480, G. striatus.
GONIDOMUS. Sw. A sub-genus of Geotrochus, Sw.Pupapagodus, Auct. Sw. p. 332.
GONIOSTOMA. Sw. A sub-genus of Bulimus, thus described, "spire elongated, of few whorls; aperture contracted at each end; lips margined; the pillar curving inwards; the base slightly notched. G. erubescens,Sw.Zool. Journ. i. pl. 5, f. 2." Sw. p. 335.
GONIOSTOMATÆ. Bl. A family belonging to the order Asiphonibranchiata, Bl. containing the genera Solarium and Trochus.
GONOSPIRA. Sw. A sub-genus of Pupa, thus described, "spire perfectly cylindrical, of equal thickness, the tip obtuse, with the whorls large; aperture oval; lips thickened; pillar with or without a plait. G. polanga,Desh.Lesson, Voy. pl. 8, f. 8." Sw. p. 333.
GRANULATED. (Granum, a grain.) Covered with minute grains, rough. The granulated lip of Oniscia, (fig. 409) will serve as an example.
GRATELOUPIA. Moulins.Fam.Nymphacea, Lam.—Descr.Equivalve, inequilateral, sub-cuneiform, rounded anteriorly, sub-rostrated posteriorly; hinge with three cardinal teeth, a series of five or six irregular, small, diverging teeth behind the umbones, and one lateral anterior tooth in each valve; ligament external; muscular impressions two; palleal impression sinuated posteriorly.—Obs.This genus (Donax irregularis, Bast.) is only known in a fossil state. Fig. 102, G. Moulinsii.
GRYPHÆA. Lam. (From Gryps, a griffin.)Fam.Ostracea, Lam.—Descr.Inequivalve, free; lower valve large, concave; with the umbo prominent, incurved; upper valve small, flat, opercular; hinge toothless, with a curved, depressed area; one muscular impression.—Obs. These shells, which approach the Oysters, are of a more regular form, and are remarkable for the curved, produced beak of the lower valve. They are only known in a fossil state, belonging to the more ancient strata. Fig. 182, G. incurva. The recent species mentioned by Lamarck is not a true Gryphæa.
GYMNOLEPAS. A generic name used by De Blainville to includeOtionandCineras, Leach.
GYMNOSOMATA. Bl. The second family of the order Aporobranchiata, in the system of De Blainville. The animals belonging to this family are destitute of shells.
GYPIDEA. Dalman. A genus of Brachiopoda, thus described, "Larger valve with the umbo rostrated, remote from the hinge; with the canal large, deltoid; bilocular within."Pentamerus, Sow. Fig. 210. 211, G. Conchidium, copied from Dalman.
GYROGONA. Lam. A genus of microscopic Foraminifera.
GYROIDINA. D'Orb. A genus of microscopic Foraminifera.
HALIOTIDÆ. Sw. A sub-genus of Calyptræa.Calyptræadilatata. Sowerby's Genera of Shells, fig. 9.
HALIOTIS. Auct. (αλς,als, sea;ους,ωτος,otos, ear.)Fam.Macrostomata, Lam. Otides, Bl.—Descr.Auriform, broad, depressed, pearly within, rough, costated, tuberculated without; spire short, flat, consisting of one or two whorls; aperture wide; ovate; columella laminar, flat,oblique; a spiral series of perforations running along the dorsal margin.—Obs.The splendid shells belonging to this genus are remarkable for the pearly iridescence of the inner surface, and the row of holes following the course of the spire. The soft parts are eaten in Guernsey and Jersey, and reckoned delicious. They belong to temperate and tropical climates. Fig. 338, H. rubra. 339, Padollus, Montf.
HALIOTOID. (Haliotisandειδος,eidos, form.) Ear-shaped.
HAMIFORM. (Hamus, a hook.) Curved at the extremity.
HAMITES. Parkinson. (Hamus, a hook.)Fam.Ammonacea, Lam.—Descr.Elongated, cylindrical, chambered, recurved at the smaller extremity, annulated; septa lobed and sinuated.—Obs. This remarkable fossil from the Baculite limestone in Normandy, differs from Baculites in being curved at one extremity, a circumstance from which its name is derived. Some small species are found in Chalk-Marle, Folkstone. Fig. 484*. H. cylindricus.
HARPA. Brug. (Harpa, a harp.)Fam.Purpurifera, Lam. Entomostomata, Bl.—Descr.Oval, ventricose, longitudinally and regularly costated; spire short, with rounded, dome-like whorls; aperture wide, emarginated; outer lip thickened, reflected, composing the last costa or rib; inner lip polished, spread over part of the body whorl, terminating in a point.—Obs.This beautiful genus of shells is so clearly defined by the regular, longitudinal ribs that adorn the external surface, suggesting the idea of a stringed instrument, that there is no danger of confounding it with any other. H. multicostata, (Buccinum costatum, Linn.) and H. ventricosa, are among the most elegant of the testaceous productions of the sea both in form and colouring; the former is rare. The recent species are not numerous, they inhabit the Indian Ocean. A fossil species occurs at Grignon, near Paris. Fig. 419, H. ventricosa.
HARPAX. Parkinson. Part ofPlicatula, Auct.
HARPULA. Sw. A group of shells separated fromVoluta, Auct. thus described, "shell generally tuberculated or longitudinally ribbed; apex of the spire papillary, smooth, and in general distorted; pillar with numerous distinct plaits; the upper, small and slender, the lower, thickest and shortest."—Type, H. Vexillum. (Voluta, Auct.)
HAUSTATOR. Montf. A genus proposed to include those species ofTurritella, Auct. which have angulated whorls.
HAUSTELLARIA. Sw. A sub-genus of Murex, consisting of species with long canal and no spines. Murex Haustellum, fig. 396.
HAUSTRUM. Humph.Purpura, Lamarck.
HELCION. Montfort. A genus composed of species of Patella, which have the apex distinctly and prominently bent forwards.Ex.P. pellucida, fig. 230.
HELENIS. Montf. A genus of microscopic Foraminifera.
HELICELLA. Fer. One of the sub-genera into which De Ferussac has divided the genus Helix, consisting of depressed species with large umbilicus, such as Helix Algira, fig. 279. Gonites Montf.
HELICIFORM. Shaped like shells of the genus Helix.
HELICIGONA. One of De Ferussac's sub-genera of the genusHelix, consisting of angulated species, such as Carocolla Lamarckii, fig. 277.
HELICINA. Lam.Fam.Colimacea, Lam. Ellipsostomata, Bl.—Descr.Globose, compressed, or angulated, generally light and thin; aperture trigonal or semilunar; outer lip thickened and generally more or less reflected; inner lip spread over the body whorl, frequently callous near the columella, which is short, and terminates in a notch, angle, or slight callosity.—Obs.This genus of land shells, distinguished from the genus Helix, by having an operculum and a thickened columellar lip, differs also from Cyclostoma in having the aperture semicircular or angular, the peritreme discontinuous and the operculum concentric. These shells are generally small in size, and simple in form. Lamarck describes only three or four species. Mr. Gray described some others in the Zoological Journal, and in a work shortly to be published by the author, a monograph of the genus will contain descriptions and figures of at least 60 distinct species; some of which have been lately brought to this country by Mr. Cuming from the Philippine Islands. They mostly belong to tropical climates.
HELICITES. Bl. Part of the genusNummulites, Lam.RotalitesandEgeon, Montf.
HELICOGENA. Fer. A sub-genus of Helix, consisting of species, which, like the common garden snail, fig. 268, are globose and simple in form.
HELICOLIMAX. Fer.Vitrina, Drap. H. Pellucida, fig. 263.
HELICOPHANTA. Fer. A sub-genus of Helix, consisting of ear-shaped species with large open apertures.
HELICOSTYLA. Fer. A sub-genus of Helix, consisting of species with numerous whorls, as H. Epistylium, fig. 281.
HELISOMA. Sw. A sub-genus of Planorbis. Sw. p. 337.
HELIX. Auct.Fam.Colimacea, Lam.—Descr.Orbicular, light, generally globular; spire short, last whorl ventricose, aperture oblique, peritreme reflected, interrupted by the most prominent part of the body whorl; columella confluent with the outer lip, and contiguous to the axis of the shell. No operculum; a thin epidermis.—Obs.The land shells composing this genus are found in all parts of the world; the common snail, H. Aspersa, is well known as a destructive animal in our gardens. The genera Helix, Achatina, Bulinus, Clausilia, Anostoma, &c., have been united under one generic name by De Ferussac, and again divided under the following sub-generic names, each of which we shall illustrate by a figure.Genus Helix:Sub-genus1,Helicophanta, consisting of species with large apertures, like Vitrina; Helix brevipes.S. gen. 2,Cochlohydra, Succinea Amphibia, Drap.S. gen. 3,Helicogena, consisting of the common species with the last whorl large; Helix Hæmastoma, H. Contusa, (Streptaxis, Gray,) H. Aspersa.S. gen. 4,Helicodonta, consisting of species with teeth or folds on the columella; Polydonta, Montf. Anostoma, Helix Nux-denticulata.S. gen. 5,Helicigona, Carocolla, Geotrochus.S. gen. 6,Helicella, consisting of depressed species with a large umbilicus; H. Citrina (Naninia, Gray.)S. gen. 7,Helicostyla, consisting of species with a simple aperture, like the Helicogenæ, but with the whorls increasing very gradually; H. epistylium.S. gen. 8,Cochlostyla, Bulinus.S. gen. 9,Cochlitoma, Achatina.S. gen. 10,Cochlicopa, Polyphemus Glans.S. gen. 11,Cochlicella, Bulinus decollatus.S. gen. 12,Cochlogena, Azeca tridens.S. gen. 13,Cochlodonta, Pupa Uva.S. gen. 14,Cochlodina, Clausilia macascarensis, Balea fragilis. The last three sub-genera are included in the genus Odostomia of Fleming. We give an example of each of these sub-divisions, for the sake of presenting the reader with the principal variations to which the genus is subject. The established genera will be characterized in their places. Fig. 254 to 281.
HELIXARION. Fer.Vitrina, Drap. Differing from Helicolimax in the structure of the animal. Fig. 262.
HEMICARDIUM. Cuv. (ἡμισυς,hemisus, half,ΚαÏδια,cardia, heart.)CardiumHemicardium, fig. 123**, and several similar species.
HEMICYCLA. Sw. A sub-genus of Helix.
HEMICYCLONOSTA—seeCardilia.
HEMICYCLOSTOMATA. Bl. The fourth family of Asiphonibranchiata, Bl. described as "more or less globular, thick, flattened on the under side; spire very short; aperture large, semilunar, entire; its outer edge hollowed; its inner or columellar edge straight, sharp and septiform." This family answers to the genusNeritaof Linnæus, and to the family Neritacea of Lamarck. It contains the genera Natica, Nerita, Neritina, and Navicella.
HEMIMACTRA. Sw. A sub-genus of Mactra, thus described: "General form ofMactra; but the cardinal teeth entirely wanting; cartilage internal, central, in a large triangular cavity; lateral teeth 2/1, distinct, lateral, striated: connected to theGlycimeri. H. gigantea,Lam.v. 472. No. 1. grandis,Sw.Sp. Nov." Sw. p. 369.
HEMIMITRA. Sw. A sub-genus of Paludomus, Sw. (Melanianæ.)
HEMIODON. Sw. A sub-genus of Anodon, described as having "Tubercles or undulations on the hinge margin. H. undulatus, purpurascens and areolata."
HEMISINUS. Sw. A sub-genus of Melania, thus described: "General shape ofMelania; but the base of the aperture is contracted and emarginate; outer lip crenated. H. lineolata, Griff. Cuv. xii. pl. 13. fig. 4."
HEMITOMA. Sw. A sub-genus of Emarginula, thus described: "Patelliform; the fissure not cut through the shell, but merely forming an internal groove. H. tricostata,Sw.Sow. Gen. fig. 6."
HEMITROCHUS. Sw. A sub-genus of Geotrochus, Sw. H. hæmastoma. Sw. p. 331.
HEPTALASMIS. Leach. (Ἡπτα,hepta, seven;ελασμα,elasma, plate) A small shell resembling Pentelasmis, from which it differs in the number of valves, being composed of seven valves according to Leach, and of eight according to Gray, who counts the dorsal valve, which is jointed, astwo, and names his genus Octolasmis. Fig. 41, H. Warwickii.
HERCOLES. Montf. A microscope shell, appearing from De Montfort's figure to resembleTrochusImperialisin shape.
HERION. Montf.Lenticulina, Bl. Microscopic.
HERMAPHRODITA. Bl. The third sub-class of Paracephalophora, Bl. divided into, Sect. 1,symmetrical, containing the orders Cirrobranchiata and Cervicobranchiata; Sect. 2,non-symmetrical, order, Scutibranchiata.
HERMES. Montf. A genus composed ofConusNussatella, Auct. and other elongated, cylindrical, striated species. Fig. 460.
HETEROBRANCHIATA. Bl. The fourth order of the class Acephalophora, Bl. containing no testaceous mollusca.
HETEROPODA. Lam. The fifth order of the class Mollusca, Lam. This order contains but one genus of shells, viz. Carinaria, fig. 488.
HETEROSTEGINA. D'Orb. A genus of microscopic Foraminifera.
HIATELLA. Daud. Fam. Lithophagidæ, Lam. A genus composed of species of Saxicava, Auct. which have sharp, angulated, posterior ridges, a circumstance which occurs to many species in a young state, which afterwards become rounded off. Fig. 95, Hiatella biaperta.
HIATULA. Sw. A genus proposed to include those species of Oliva, Auct. which have widened apertures.Ex.O. Subulata, fig. 458.
HIBOLITHES. Montf. A genus composed of species of Belemnites, Auct. which are swelled towards the apex, and contracted near the centre. B. Hastatus, Auct. fig. 468.
HIMANTOPODA. Schum.Malleus, Auct.
HINGE. The edge of the bivalve shells near the umbones, including the teeth and ligament.
HINNITES. Defr. A generic name proposed forPecten Pusio, Auct. remarkable for the irregularity of the outer surface, which would almost lead to the belief of its being an attached shell. Fig. 173, H. Pusio.
HIPPAGUS. Lea. (Horse boat.) A minute fossil shell, resembling Isocardia in form, but destitute of hinge teeth. H. Isocardioides, fig. 128.
HIPPOCHRENES. Montf. Species ofRostellaria, Auct. with the outer lip spread. Fig. 403. R. Columbaria.
HIPPONYX. (Ἱππος,hippos, horse;ονυξ,onyx, nail or hoof.)Fam.Rudistes, Lam.—Descr.Inequivalve, sub-equilateral, rather irregular, destitute of ligament and hinge teeth; lower valve attached, flat, sub-orbicular, with a muscular impression, composed of two lunulate portions, meeting at one extremity, and presenting the form of a horse-shoe; upper valve conical, with the apex inclined backwards, and the muscular impression marginal.—Obs.The earlier naturalists having only met with the upper valve of these shells, placed them among the patelliform univalves; to some of which, particularly Pileopsis, they bear a very strong resemblance. The species of Hipponyx are numerous, and till lately only known in a fossil state. The recent species belong to tropical climates: the fossil species are found in the tertiary beds. Fig. 199, H. Cornucopia.
HIPPOPODIUM. Conybeare.Fam.Cardiacea, Lam.—Descr.Equivalve, obliquely transverse, heavy, deep, inequilateral, umbones incurved; ventral margin sinuated, so as to give a bilobed appearance to the shell; hinge incrassated, with one rugged oblique tooth.—Obs.These fossils are found in the upper beds of Lias. Fig. 129, H. Ponderosum.
HIPPOPUS. Lam. (Ἱππος, hippus;πους,pous, foot.)Fam.Tridacnacea, Lam.—Descr.Equivalve, inequilateral, regular, subquadrate; lunule closed, flat, with crenulated edges; ventral margin deeply undulated; external surface fluted, with radiating ribs, which are transversely fringed with rows of tubular spines; hinge margin thick, with two long, compressed posterior lateral teeth in one valve, three in the other; ligament marginal, external.—Obs.The shell thus described is rightly separated from Tridacna, on account of the anterior dorsal margins being closed; whereas in Tridacna there is a wide hiatus. Only one species of this genus is known, which receives its name from its resemblance in form to a horse's foot, when held with the flat anterior dorsal margin downwards. Few shells are found to concentrate so many beauties as the Hippopus Maculatus, commonly called the Bear's-paw-clam; the delicate whiteness of the interior, the undulating edge, the radiated fluted columns, adorned at intervals by crisped fringes, and the richness of the variegated colouring, are such as to secure the admiration of the most superficial observer. From the Indian Archipelago. Fig. 156, H. Maculatus.
HIPPURITES. Montf.Fam.Orthocerata, Lam. Rudistes, Bl.—Descr.Tabular, rude, irregular, attached; lower valve cylindrical, more or less lengthened, apparently divided into sections by septa (considered by some authors as merely projecting layers of growth) having one or two lateral tubes within; upper valve round, flat, fixed on the aperture of the tubular valve like an operculum.—Obs.This genus is known only in a fossil state, and but very imperfectly. Lamarck places it among his chambered Cephalopoda, &c. De Blainville, considering it a true Bivalve, enumerates it among his Rudistes. Cretaceous group. Fig. 198, H. Cornucopia.
HORTOLUS. Montf.Spirolina, Lam. Microscopic.
HYALÆA. Auct. (Hyalus, glass.)Fam.Pteropoda, Lam. Thecosomata, Bl.—Descr.Globose, glassy, transparent, with a triangular opening at the upper part where the dorsal portion advances beyond the ventral; ventral portion vaulted; dorsal more flat; lower extremity tridentate.—Obs.The singular structures composing this genus were formerly taken for bivalves, and named Anomia Tricuspidata, &c. They are now known to belong to the class of molluscous animals, called Pteropoda, from the wing-shaped organs of locomotion. A species of Hyalæa occurs in Sicily in a fossil state. Recent species are found in the Mediterranean, Atlantic, and Indian Oceans. Fig. 226, H. Tridentata.
HYALINA, Studer.Vitrina, Drap.
HYALINE. (Hyalus, glass.) Glassy, thin, transparent—Ex.Carinaria Mediterranea, fig. 488.
HYDROBRANCHIATA. Bl. The first section of the order Gasteropoda, Lam. containing Molluscs which breathe water only; divided into the families Tritoniana, Phyllidiana, Semi-phyllidiana, Calyptracea, Bullæana, and Aplysiana.
HYGROMANES. Fer. A sub-division of Helix, containing H. limbata, Auct. &c. Gray's Turton, p. 143.
HYRIA. Lam. A genus composed of species of Nayades, distinguished by their alated dorsal margins, and lamellated lateral teeth. South America.Hyriacorrugata, fig. 143, Hyria Syrmatophora, fig. 144.
HYRIDELLA. Sw. A genus of "Hyrianæ," Sw. described as differing fromHyria, Auct. in having a cardinal as well as a lateral tooth in each valve. Sw. p. 380.
HISTRIX. Humph.Ricinula, Auct.
JANERA. Schum. A genus composed of species of Pecten, Auct. having oblique plicæ or calli on each side of the ligamentary pit.Ex.P. plica, fig. 172. Decadopecten, Rüppell.
JANTHINA. Auct. (Janthum, a violet.)Fam.Neritacea, Lam. Oxystomata, Bl.—Descr.Sub-globose, thin, fragile; spire short, consisting of few whorls; aperture angulated, at the anterior junction of the inner and outer lips; columella tortuous, contiguous to the axis; outer lip thin, sinuated in the centre.—Obs.The shells composing this genus are celebrated for their beautiful purple colour. The animal possesses a small vesicular process, which keeps it floating on the surface of the water; it exudes a purple secretion when irritated. It is occasionally floated on to the shores of most temperate and tropical countries. Fig. 333, J. Fragilis.
JATARONUS. Adanson.Chama, Auct.
IBERUS. Montf.Carocolla, Lam.
IBLA. Leach.Fam.Pedunculated Cirripedes, Lam.—Descr.Four valves, posterior pair elongated, anterior pair short, triangular; pedicle cylindrical, contracted at the base, hairy.—Obs.I. Cuveriana (fig. 40) is brought from Kangaroo Island.
ICTHYOSARCOLITES. Desmarest.Fam.Ammonacea, Lam.—Descr.Chambered, slightly arcuate, laterally compressed; septa simple, leaving triangular articulations imbricated like the thick muscles of a fish.
JESITES. Montf. A minute fossil resemblingGaleolaria.
ILOTES. Montf.Orbiculina, Bl. A genus of microscopic Foraminifera.
IMBRICARIA. Schum.Conohelix, Sw.
IMBRICATED. (Imbrex, a tile.) A shell is said to be imbricated when the superficial laminæ are arranged over each other in the manner of tiles.
IMPERATOR. Montf. A genus composed of species of the genusTrochus, Auct. with whorls angulated and stellated, having an umbilicus.Ex.T. Imperialis. Some of the shells named Imperator in the British Museum belong to the genus Calcar, Montf. having no umbilicus.
IMPRESSION. SeeMuscular Impression.
INCRASSATED. (Crassus, thick.) Thickened, as the hinge of Glycimeris, fig. 67.
INCURVED. Turned inwards or bent forwards. Applied to symmetrical shells, when the point of the apex turns towards the anterior extremity, as in Patella. The apex of a shell is said to be incurved when it is bent inwards, but not sufficiently so to be described as spiral.Ex.Ammonoceras, Lam. fig. 477.
INDENTED. (In, in;dens, a tooth.) Exactly the reverse ofDentated; meaning a series of small cavities, such as might be produced by the entrance of teeth. The cast of a dentated surface would be indented.
INEQUILATERAL. (Æquus, equal;latus, a side.) A term applied to a bivalve shell when its extent on one side of the umbones is greater than that on the other. When the sides are nearly equal, the termsub-equilateralis used.
INEQUIVALVE. (in;æquus, equal;valva, valve.) The two principal valves differing from each other in diameter or convexity.
INFERIOR VALVE is that which is attached to sub-marine bodies. Only applied to attached bivalves.
INFEROBRANCHIATA. Bl. The fourth family of the second section of Paracephalophora Monoica, Bl. containing no testaceous mollusca.
INFLATED. Swelled, as Bulla, fig. 250, 252. This term can only be applied to rotund shells of a light, thin texture. In other cases we should use the wordVentricose.
INFLECTED. Turned inwards. This term is applied to the outer lip of a spiral shell when it turns towards the body whorl. This is the case in Cypræa, fig. 446. SeeReflected.
INFUNDIBULUM. Montf. (A funnel.) A genus formed of those species ofCalyptræa, Lam. which, having a spiral septum, so nearly resemble Trochus that some authors have placed them in that genus. One species named Patella Trochiformis. Recent from South America, fossil from the tertiary beds. Fig. 237, 238, Calyptræa (Infundibulum) Pileus.
INNER LIP. That edge of the aperture of an univalve shell which is near to the imaginary axis, as distinguished from the outer lip, or that which is on the opposite side.
INOCERAMUS. Sow.Fam.Malleacea, Lam. Margaritacea, Bl.—Descr.Thick, inequivalve, sub-equilateral, triangular, deep, with the umbones incurved; hinge formed of a series of transverse grooves.—Obs.The larger valves of these fossil shells resemble the larger valve of Gryphæa; but the hinge is quite distinct. The species described in Mineral Conchology are found in the blue marl, at Folkstone, and in the chalk. I. Lamarckii, (Catillus, Brong.) fig. 167.
INTERNAL CAST. The mould of a fossil shell, composed of matter which entered the shell in a soft state, and has subsequently hardened, when, the shell dropping off, the hardened substance which filled it is left to represent its internal form.
INTERNAL LIGAMENT. A term used by some conchological writers signifying that the ligament of a bivalve shell is placed within the closed part of the hinge, so as not to be seen when the valves are shut. But the substance, formerly called the internal ligament, is now distinguished from the true ligament both in structure and use; and is now more properly called the cartilage, so that when the ligament is said to be internal, it must be understood that the internal cartilage is unaccompanied by any ligament properly so called, and when a shell is described as having two ligaments, as in the case of Amphidesma, it means that the two substances are so far removed from each other in the hinge that they are no longer confounded together.
INTERNAL SHELL is one which is enclosed in the soft parts of the animal, as a bone is enclosed in the flesh of a human body. The Limax, or common garden slug, which has a testaceous shield beneath its mantle, is an instance of this.
IO. Lea. A genus composed of several species of fresh-water shells which are considered as differing from Melaniæ in having the anterior termination of the aperture produced into a point in some degree resembling the caudal canals of shells belonging to the family of Canalifera, which are marine. Io fusiformis and spinosus are described and figured in Lea's work on the genus Unio.
JODAMIA. Defr. A genus resembling Birostrites, except that in Jodamia one valve overwraps the other, while in Birostrites the circumference of the valves is equal.
IPHIGENIA. Gray. A sub-genus of Clausilia, C. biplicata, &c. Auct. Gray's Turton, p. 214.
IRIDEA. Sw. A genus of "Hyrianæ," Sw. thus described:—"Oblong ovate; bosses small, depressed, sulcated; inner cardinal tooth placed beneath the outer. I. granosa,Lam.En. Méth. 248. fig. 9."
IRIDINA. Auct. A genus belonging to the Nayades, and resembling theAnodontæ, Auct. but its peculiar characteristic is that the hinge lamina is tuberculated or crenulated in its whole length. Sowerby unites all the genera of the family into the genusUnio. Fig. 150, I. Elongata.
IRREGULAR SHELLS, are those which, being attached to, or imbedded in other marine bodies, have no constant form, but are modified in shape according to the substances to which they are fixed, as the Chamacea, fig. 153 to 155.
IRUS. Oken. ComprehendingPandora,Petricola,Saxicava, &c.
ISOCARDIA. Lam. (Ισος,isos, similar;ΚαÏδια,cardia, heart.)Fam.Cardiacea, Lam. Chamacea, Bl.—Descr.Cordiform, regular, equivalve, ventricose, with distant, diverging, involute, free umbones; hinge with two compressed cardinal, and one distant, compressed lateral teeth in each valve; ligament external, bifid, diverging in the direction of the umbones.—Obs.The shells composing this genus are remarkable for the beautiful curvature of the diverging umbones. European and Chinese Seas. Fig. 126, I. Moltkiana.
KEEL. A flattened ridge, resembling the keel of a ship. As that on the back of Carinaria vitrea, fig. 488, and those on the whorls of some spiral shells. A shell characterized by a keel or keels is said to be carinated.
KELLIA. Turton,MyaSuborbicularis, Montague.
LABIS. Oken.Monodonta, Lam.
LABIUM, or inner lip,—is used to express that side of the aperture which is nearest to the axis and generally contiguous to the body whorl. The lower part of this, when sufficiently distinct from that part which overwraps the body whorl, is called the Columella.
LABRUM, or outer lip,—is the edge of the aperture at the greatest distance from the axis.
LACINEA. Humph.Chama, Lam.
LACUNA. Turt.Fam.Turbinacea, Lam.—Descr.Globose, thin, covered with a smooth epidermis; spire short, consisting of few rapidly increasing whorls; aperture semilunar, rounded at the extremities; columella oblique, reflected over part of the umbilicus; umbilicus forming a lengthened area behind the columella. Northern shores. Fig 364, L. Pallidula.
LAGENULA. Montf. A genus of microscopic Foraminifera.
LAMELLATED. (Lamella, a thin plate.) When the layers of which a shell is composed, instead of being compacted into a solid mass, are separated, overlying each other in the manner of tiles, with the edges prominent, the structure is said to be lamellated or foliaceous.
LAMELLIBRANCHIATA. Bl. The third order of the class Acephalophora, Bl. consisting of bivalve shells, divided into the families Ostracea, Subostracea, Margaritacea, Mytilacea, Polydontes, Submytilacea, Chamacea, Conchacea, Pylorides, Adesmacea.
LAMELLIPEDES. Lam. (Lamella, a thin plate,pes, a foot.) The third section of the order Conchifera Dimyaria, containing bivalves, with the foot of the animal broad and thin; divided into the families Conchacea, Cardiacea, Arcacea, Trigonacea, Nayades. Fig. 111. to 152.
LAMPAS. Montf.Lenticulina, Bl. A genus of microscopic Foraminifera.
LAMPRODOMA. Sw. A genus of "Olivinæ," Sw. thus described:—"Mitriform; spire produced, conic; resemblingMitrellain shape, but the suture is channelled; the aperture effuse at the base, contracted above; lower half of the pillar with 6 to 7 plaits. Volutella, Zool. Ill. ii. series, pl. 40. f. 1. (fig. 86.)" Sw. p. 321.
LAMPROSCAPHA. Sw. A sub-genus of "Anodontinæ," Sw. thus described:—"Shell not winged, elongate, pod-shaped; teeth none; bosses near the anterior extremity. Tropical America only? L. ? elongata.Sw.Zool. Ill. i. 176. ensiforme,Spix.Braz. Test. siliquosa. Braz. Test. pygmæa. Ib." Sw. p. 381.
LAMPROSTOMA. Sw. A sub-genus of Canthorbis (Trochus), described at p. 350, Lardn. Cyclop. Malac.
LAMPUS. Humph.Terebratula, Lam.
LANCEOLATE. Lengthened like a lance.
LANISTES. Montf. Reversed species ofAmpullaria, fig. 319.
LAPLYSIA. SeeAplysia.
LAPLYSIACEA. Lam. (properly Aplysiacea) A family belonging to the first section of the order Gasteropoda, Lam. containing the genera Aplysia and Dolabella. Fig. 254, 255.
LARVA. Humph.Fissurella, Lam.
LATERAL. (Latus, a side.) The lateral teeth are those which, taking their rise near the umbones, proceed to some distance towards the sides of the shell; as distinguished from the cardinal teeth, which receive their full developement close to the umbones. Lateral muscular impressions are those which are placed at a distance from each other, on the opposite sides of the shell.
LATIAXIS. Sw. A genus of "Eburninæ," Sw. corresponding with the genus Trichotropis. Sow. (Sw. Malac. p. 306.)
LATIRUS. Montf. A genus composed of species ofFusus, Auct. which have an umbilicus and are turriculated.
LAURIA. Gray. A sub-genus ofPupa, containing P. umbilicata, &c. (Gray's Turton, p. 193.)
LEGUMINARIA. Schum. A genus composed of species ofSolen, Auct. which have an internal longitudinal bar or rib. Fig. 61. S. Radiatus, Lam.
LEILA. Gray? Described as having the hinge edge smooth like Iridina, but having a "sharp siphonal inflexion." (Syn. B. M. p. 142.)
LEIODOMUS. Sw. A genus of "Buccininæ," Sw. consisting of Terebra vittata and other similar species. This genus corresponds with Bullia, Gray.
LEIOSTOMA. Sw. A genus of "Fusinæ," Sw. thus described, "Equally fusiform," (with Fusus) "but ventricose in the middle; shell entirely smooth, almost polished; inner lip thickened, and vitreous; base of the pillar very straight. Fossil only. (fig. 75.) L. bulbiformis. En. Méth. 428. f. 1."
LEMBULUS. Leach. A genus composed of oval species ofNucula, resembling N. margaritacea, fig. 137.
LENDIX. Humph.Pupa, Lam.
LENGTH. SeeMeasurement.
LENTICULAR. (Lens.) Of a circular, convex form, as Pectunculus, fig. 134.
LENTICULINA. Lam. A genus of microscopic Foraminifera.—Descr.Lenticular, sub-discoidal, compressed, convolute, symmetrical; aperture notched; chambers few in number; visible on the exterior, radiating from the centre of the disk.
LEPADICEA. Bl. The first family of the class Nemantopoda, Bl. This family consists of the same animals which constitute the Pedunculated Cirripedes of Lamarck, and part of the genus Lepas in the system of Linnæus. It contains the genera Gymnolepas, Pentalepas, Polylepas and Litholepas.
LEPAS. (Λεπας,lepas, a rock.) The Linnæan name Lepas contains all the Cirripedes or Multivalves, the different kinds of which are not distinguished in the accounts given by early writers of the habits of the animals. (Fig. 14 to 43.) It was formerly applied to the Limpets or Patella. In fact, the ancient definition was "Concha petræ adhærens," and would apply to any shells attached to rocks.
LEPTÆNA. Dalman. A genus belonging to the Brachiopoda; and thus described:—"Hinge compressed, rectilinear, frequently exceeding the width of the shell." It forms part of the genus Producta, Sow. Fig. 206, L. depressa.
LEPTOCONCHUS. Rüppell. (Λεπτος,leptus, thin;Κογχος,conchos, shell.) This shell resembles a youngMagilusin general appearance, although the animal is said to differ. In the young Magilus also, the inner lip is reflected over the body whorl, which is not the case in Leptoconchus. Red Sea. Fig. 11.
LEPTOCONUS. Sw. A sub-genus of Conus, consisting of Conus grandis, amadis, duplicatus, Australis, &c. Sw. p. 312.
LEPTOLIMNEA. Sw. A sub-genus of Limnea, described as being nearly cylindrical. Limnea elongata, Sow. Gen. fig. 6.
LEPTON. Turton.SolenSquamosus, Montague, and other species described as "flat, nearly orbicular, equivalve, inequilateral, a little open at the sides. Hinge of one valve with a single tooth, and a transverse linear lateral one on each side; of the other valve, with a cavity in the middle and a transverse deeply cloven lateral tooth each side, the segments of which divaricate from the beak." To represent this genus we have figured L. Squamosum in the plates, fig. 62. British.
LEPTOSPIRA. Sw. A sub-genus of Bulinus, thus described: "Spire excessively long, sub-cylindrical; body whorl largest; outer lip thickened; aperture oval; no teeth, striata,Sw.Chem. 135. f. 1226. signataSw." Sw. p. 335.
LEUCOSTOMA. Sw. A genus of "Achatina," Sw. described as resembling Achatinella, but having a "thick pad" at the top of the "upper lip," and another over the base. L. variegata, Sw. Lardn. Cyclop. Malac. fig. 24. p. 172.
LEUCOTUS. Sw. A sub-genus of Natica, described as intermediate between Sigaretus and Lacuna.Sigaretuscancellatus, Lam. (Sw. Malac. p. 346.)
LICIUM. Humph.Ovula, Lam. (Ovulum.)
LIGAMENT. (FromLigo, to bind.) The true ligament is always external, and serves the purpose of binding the two valves of a shell together externally by the posterior dorsal margins. There is another substance, called by Gray theCartilage, which is elastic and of a condensed fibrous structure, placed within the ligament, either close to it, or at a more interior part of the shell; it is sometimes contained in a pit, formed for its reception, in the centre of the hinge. This substance, being elastic, keeps the valves open, unless drawn together by the counteracting force of the adductor muscles. When conchologists speak of a shell as having the ligament external, the real meaning is that these two substances are so close together as in appearance to constitute one body placed outside the shell so as to be seen when the valves are closed. When two ligaments are spoken of, as in Amphidesma, the meaning is that the cartilage occupies a separate place on the hinge.
LIGAMENTIFEROUS. (Ligamentum, a ligament,fero, to bear.) Having or containing the ligament, as the cardinal pit in Mya, fig. 71.
LIGULA. Leach. A genus containing the more rounded and less gaping species ofLutraria, Auct. Fig. 77, Lutraria Papyracea.
LIGULATE. (Ligula, a slip, a shoe-latchet.) Thin, slender, like a slip, or neck of any thing, as the anterior muscular impression of Lucina, fig. 104.
LIGUMIA. Sw. A sub-genus of Unio, thus described:—"Very long and pod-shaped; bosses depressed; cardinal teeth moderate. S. recta. Lam. vi. 1. p. 74." Sw. p. 378.
LIGUUS. Montf. A genus containing species ofAchatina, Auct. which have rounded apertures and lengthened spires, differing from hisPolyphemi, which have lengthened apertures. A. virginea, Auct. fig. 286, is the type of this genus.
LIMA. Brug. (Lima, a file.)Fam.Pectinides, Lam. Subostracea, Bl.—Descr.Equivalve, inequilateral, compressed, oblique-auriculated, oval, radiately ribbed or striated, imbricated, covered with a light brown epidermis; hinge with a triangular disc between the umbones, divided in the centre by a triangular ligamentary pit without teeth; muscular impression one, sublateral, sub-orbicular.—Obs.The shells thus described are marine, two or three species being found on our coasts, and fossil species occurring in Lias, inferior Oolite, Calcaire-grossiér, &c. They differ from Pecten in having a wide hiatus for the passage of a byssus, by which they are occasionally attached, and also in the triangular disc, which separates the umbones. The animal makes use of the valves of his shell as natatory organs, working them like fins or paddles, and by this means proceeding at a rapid rate through the waters. L. Squamosa, fig. 174.
LIMACINA. Cuv. (Limax, a snail.)Fam.Pteropoda, Lam.—Descr.Papyraceous, fragile, planorbicular, sub-carinated, obliquely convolute; spiral side rather prominent, the other side umbilicated; aperture large, entire, not modified, peristome sharp.—Obs.This isSpiratella, Bl. The shell figured as Limacina in Sowerby's Genera, under "pteropoda," is anAtlanta. Our representation of Spiratella Limacinea, fig. 224. is copied from Blainville.
LIMACINEA. Lam. A family of the order Gasteropoda, Lam. including the following