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The sub-kingdom of ECHINODERMATA includes the above groups comprised in the Classes Crinoidea, Asteroidea, Ophiuroidea and Echinoidea. Besides these are the less important classes of the Cystidea or sac-shaped echinoderms (of which no definite remains are recorded from Australian rocks); the Blastoidea or bud-shaped echinoderms (of which four genera are known from Australia); the Edrioasteroidea or sessile starfishes (unknown in Australia); and the Holothuroidea or sea-cucumbers (represented as fossils by the skin spicules and plates, an example of which has been recorded from Australia).
CRINOIDEA, or Sea-lilies.
Crinoidea, their General Structure.—
These often beautiful and graceful animals resemble a starfish mounted on a stalk. They are composed of calcareous joints and plates, and are therefore important as rock-formers. The stalk or column may be either short or long, and is generally rooted, in the adult stage, in the mud of the sea-floor. Fossil Crinoids were sometimes furnished witha coiled termination, which could be entwined around such objects as the stems of sea-weeds. The crinoid column is composed of numerous plates, and is round or pentagonal. Upon this is fixed the calyx or cup, with its attached arms, which serve to bring food to the mouth, situated on the upper part of the cup. The arms are grooved, and the water, being charged with food particles (animalcula), pours down these channels into the mouth. The stem elevates the animal above the mud or silt of the sea-floor, thus making it more easy for it to obtain its food supply. The stalks of fossil Crinoids sometimes reached the enormous length of 50 feet. Their calcareous skeleton is built upon a plan having five planes of symmetry; this pentamerism is found throughout the crinoids, the blastoids and the free-moving echinoderma. Crinoids range from moderately shallow- to deep-water, and at the present day are almost restricted to abyssal conditions. The more ancient types usually found their habitats amongst reefs or in comparatively clear water, where there was a marked freedom from sediment, although that was not an essential, as seen by their numerous remains in the Australian mudstones and sandstones.
Cambrian Crinoids.—
The group of the Crinoidea first appears in the Upper Cambrian, and persists to the present time. In North America the genusDendrocrinusoccurs in the Cambrian and Ordovician; and some stem-joints from the Upper Cambrian limestone of the Mount Wellington district, Victoria, may be provisionally referred to this genus.
Fig. 76—FOSSIL CRINOIDS.A—(?) Pisocrinus yassensis, Eth. fil. Side of calyx. Silurian. Yass, New South Wales.B—(?) Pisocrinus yassensis, Eth. fil. Dorsal Surface. Silurian. N. S. W.C—Botryocrinus longibrachiatus, Chapm. Silurian. Flemington, Vict.D—Helicocrinus plumosus, Chapm. Stem, distal end. Brunswick, Victoria.E—Phialocrinus konincki, Eth. fil. Carbopermian (Up. Mar. Ser.) Nowra, New South Wales.F—Isocrinus australis, Moore sp. L. Cretaceous. Wollumbilla, Q’ld.
A—(?) Pisocrinus yassensis, Eth. fil. Side of calyx. Silurian. Yass, New South Wales.B—(?) Pisocrinus yassensis, Eth. fil. Dorsal Surface. Silurian. N. S. W.C—Botryocrinus longibrachiatus, Chapm. Silurian. Flemington, Vict.D—Helicocrinus plumosus, Chapm. Stem, distal end. Brunswick, Victoria.E—Phialocrinus konincki, Eth. fil. Carbopermian (Up. Mar. Ser.) Nowra, New South Wales.F—Isocrinus australis, Moore sp. L. Cretaceous. Wollumbilla, Q’ld.
Ordovician Crinoids.—
No undoubted Crinoid remains have been found in the Australian Ordovician; although many genera are found elsewhere in that system, chiefly in N. America, asReteocrinus,Hybocrinus,HeterocrinusandDendrocrinus, and in Europe and North America, asRhodocrinusandTaxocrinus.
Silurian Crinoids.—
The Silurian Crinoidea of Australia are largely represented by the remains of the columns or stalks, which are often found in such abundance as to constitute large masses of sub-crystalline limestone, as that of Toongabbie, Victoria. The columns of the Crinoids do not usually possess sufficient charactersto enable the forms to be identified. There are, however, more perfect and identifiable remains of several very interesting generic types in the Silurian faunas as follows:—
In New South WalesPisocrinusis represented with some reservation by (?)P. yassensis, found at Limestone Creek, near Yass (Fig. 76 A, B).
In Victoria,Helicocrinus plumosusandBotryocrinus longibrachiatusoccur at Brunswick and Flemington, respectively (Fig. 76). The former is a delicate and handsome species, having a small cup with finely pinnate arms, which are forked once, and with a pentagonal stem coiled at the distal end (see Frontispiece). The genusBotryocrinusis found in rocks of a similar age in North America and England.Hapalocrinus victoriae, a member of the Platycrinidae, has been described from the mudstone of South Yarra, near Melbourne. The species above mentioned are of Melbournian age, belonging to the lower stage of the Silurian system.
Devonian Crinoids.—
In the Middle Devonian of Queensland, fragmentary crinoid stems are found interbedded with the limestone of the Broken River.
Thin slices of the limestone of the same age from Buchan, Victoria, show numerous ossicles and stem-joints of Crinoids.
Similar remains have also been recorded from the Devonian of the Kimberley district and the Gascoyne River in Western Australia.
Carboniferous Crinoids.—
The Carboniferous (Star Beds) of Queensland has yielded remains ofActinocrinus.
The Matai Series of New Zealand, which may be regarded as almost certainly of Carboniferous age, contains remains of aCyathocrinus, found in the limestone of the Wairoa Gorge.
Carbopermian Crinoids.—
The Carbopermian (Upper Marine Series) of New South Wales yields the interesting Crinoid having a large, globular cup, known asPhialocrinus; the best known species of this genus areP. konincki(Fig. 76 E) andP. princeps. Beds of the same age in New South Wales, also in the Upper Marine Series, contain the aberrant Crinoid with strongly sculptured plates of the calyx in the decorticated condition,Tribrachiocrinus clarkei.
PoteriocrinusandPlatycrinusare, with some reservation, recorded from the Gympie Series at Stanwell and the marine beds of the Bowen River Coal-field respectively, both in Queensland.
In Western Australia the Carbopermian rocks of the Gascoyne River are known to contain crinoid stems, tentatively referred to either the Rhodocrinidae or the Actinocrinidae. There is also a species ofPlatycrinusknown from the Gascoyne and Irwin Rivers, and from the Kimberley District.
Triassic Crinoids.—
The Kaihiku Series of Nelson, New Zealand, has yielded some crinoid stems, but the genus has not yet been determined.
Cretaceous Crinoids.—
In the Lower Cretaceous Limestone of Queensland, at Mitchell Downs and Wollumbilla, a typical Crinoid, closely allied to the livingPentacrinusis found, namely,Isocrinus australis(Fig. 76 F).
The Upper Cretaceous opal deposits of White Cliffs in Wilcannia, New South Wales, contain many opalised fossil remains, amongst them beingIsocrinus australis, already noticed as occurring in the Lower Cretaceous of Queensland.
Cainozoic Crinoids.—
Pentacrinus stellatusis a species founded on some deeply indented pentagonal stem-joints found in the Oamaru Series (Miocene) at Curiosity Shop, South Canterbury, New Zealand, and also occurring in the Chatham Islands. This species has been identified in the Aire Coastal beds in Victoria, of the same age. Another generic type,Antedon, the beautiful “Feather Star,” is frequently met with in Janjukian strata in Victoria and South Australia, as at Batesford and Mount Gambier, represented by the denuded crown and the ossicles of the arms of a comparatively large species; whilst another and smaller form has been described from beds of the same age from borings in the Victorian Mallee, under the name ofA. protomacronema.
BLASTOIDEA—Bud-shaped Echinoderms.
Distribution and Characters of Blastoidea.—
This forms a small class which has a few representatives in the rocks of Australia. Elsewhere they are chiefly of Devonian and Carboniferous ages. In Australia they are confined, so far as known, to sediments of the Carboniferous System. The animal was rooted to the sea-floor and a jointed stem was usually present. The cup or theca, as before noted, is bud-shaped, and consists of basal, radial and deltoid plates, the edges of which are folded inwards intothe thecal cavity, and thus the internal organs came into contact with the incurrent water. The cup bears five food grooves, bordered by numerous arms or brachioles, which directed the incurrent particles into the thecal cavity.
Carbopermian Blastoids.—
Three genera of blastoids have been recorded from the Gympie Beds, or Carbopermian, of the Rockhampton District of Queensland. They are,Mesoblastus,GranatocrinusandTricoelocrinus. A similar fossil in beds of like age, and provisionally referred to the genusMetablastus, has been lately recorded from Glenwilliam, Clarence Town, New South Wales.
ASTEROIDEA, or Starfishes.
Characters of True Starfishes.—
These free-moving echinoderms are usually five-sided, though sometimes star-shaped, with numerous arms surrounding a central disc. The mouth is central on the under side of the disc, and the anus above and near the centre (excentric), the latter being covered by a porous plate called the madreporite. The hydraulic system of starfishes consists of tubes extending along the grooved arms and giving off side branches which end in processes called podia and terminating in suckers. The podia pass through pores in the floor plates of the grooves, and communicate within the body with distensions called ampulla. By this means the podia serve as feet, and can be withdrawn by the expulsion of the water in them into the ampulla. The stout flexible covering of the starfish is strengthened by calcareous plates and bars,owing to the presence of which they are often preserved as fossils.
Fig. 77—FOSSIL STARFISH.A—Palaeaster smythi. McCoy sp. Silurian. Flemington, Victoria.B—Urasterella selwyni, McCoy. Silurian. Kilmore, Victoria.C—Palaeaster giganteus, Eth. fil. Carbopermian. Near Farley, New South Wales.D—Pentagonaster sp. Tertiary (Janjukian). Bore in Mallee, Victoria.
A—Palaeaster smythi. McCoy sp. Silurian. Flemington, Victoria.B—Urasterella selwyni, McCoy. Silurian. Kilmore, Victoria.C—Palaeaster giganteus, Eth. fil. Carbopermian. Near Farley, New South Wales.D—Pentagonaster sp. Tertiary (Janjukian). Bore in Mallee, Victoria.
Silurian Starfishes.—
The oldest Australian fossil Starfishes are found in the Silurian. In Victoria they occur in some abundance in the lower, Melbournian, series, but appear to be absent or at all events very scarce in the upper, or Yeringian series. The commonest genus isPalaeaster, of which there are two species,P. smythi(Fig. 77 A) andP. meridionalis, found alike in the sandy and argillaceous strata near Melbourne.Urasterellais another genus found in the Silurian rocks near Melbourne, in which the marginal series of plates seen inPalaeasterare wanting, giving to the starfish a slender, long-armed aspect (Fig. 77 B).
Carbopermian Starfishes.—
In the Lower Marine Series of the Carbopermian of New South Wales a very large species ofPalaeasteroccurs (P. giganteus), measuring 7 inches from point to point across the disc (Fig. 77 C). Two other species of the same genus occur in this series (P. stutchburiiandP. clarkei) the latter also ranging into the Upper Marine Series.
Cainozoic Starfishes.—
No remains of true Starfishes have been recorded from Australia between the Carbopermian and the Tertiary systems. In the Janjukian Series of Victoria the marginal plates of a species ofPentagonasterare typical fossils. They have been recorded from Waurn Ponds, Spring Creek near Torquay, and Batesford (Fig. 77 D). In the Mallee Bores, both marginal and abactinal plates of this genus are found in polyzoal limestone (Miocene).Pentagonasteralso occurs in the Lower Muddy Creek beds (Oligocene), and the Upper beds of the same locality (Lower Pliocene). A species ofAstropectenhas been described from the Waikari River, New Zealand (Oamaru Series).
OPHIUROIDEA, or Brittle-stars.
Characters of Brittle-Stars.—
The Brittle-stars are frequently found at the present day cast up on the fine sandy beaches of the coast. They are easily distinguished from true starfishes by having a definite central disc, to which the arms are attached. The arms are used for locomotion and prehension, and have their grooves coveredover with plates. The ossicles of the arms are moveable and controlled by muscles which enable them to be used as feet. The lower surface of the disc has a central arrangement of five rhomboidal sets of jaws, formed of modified ossicles, called the mouth frame, whilst the upper surface bears, between one set of arms, the madreporite or covering plate to the water vascular system, as in starfishes.
Fig. 78—Protaster brisingoides, Gregory.Negative cast of the calcareous skeleton. Nat. size.Silurian Sandstone, Flemington, Victoria.(Nat. Mus. Coll.)
Fig. 78—Protaster brisingoides, Gregory.Negative cast of the calcareous skeleton. Nat. size.Silurian Sandstone, Flemington, Victoria.(Nat. Mus. Coll.)
(Nat. Mus. Coll.)
Silurian Brittle-Stars.—
The Brittle-stars in Australia first appear in the Silurian, but in England and Bohemia date back to the Ordovician.Protasteris the commonest genus, and is represented byP. brisingoidesof the Melbournian stage of Silurian strata at Flemington (Fig. 78). It also occurs rarely in the Yeringian beds at Yering, both Victorian localities. A very ornamental form,Gregoriura spryi, occurs in the samedivision of the Silurian at South Yarra. In this fossil the delicate spines attached to the adambulacral ossicles are well preserved and form a marginal fringe to the arm (Fig. 79).Sturtzurais another Silurian genus, found in the Wenlock of England and in the Melbournian of Flemington, Victoria.
Fig. 79—A Brittle-Star.(Gregoriura spryi, Chapm.)Nat. size. From the Silurian Mudstone of South Yarra, Victoria.(Nat. Mus. Coll.)
Fig. 79—A Brittle-Star.(Gregoriura spryi, Chapm.)Nat. size. From the Silurian Mudstone of South Yarra, Victoria.(Nat. Mus. Coll.)
(Nat. Mus. Coll.)
Cainozoic Brittle-Stars.—
From the Victorian Cainozoic beds, in the Lower Pliocene of Grange Burn, Hamilton, a vertebral ossicle of an ophiurian has been obtained, which has been provisionally referred to the genusSigsbeia.
ECHINOIDEA, or Sea-urchins.
This group is an important one amongst Australian fossils, especially those of Cainozoic age.
Characters of Sea-urchins.—
Echinoids are animals enclosed in a spheroidal box or test composed of numerous calcareous plates, disposed geometrically as in the Starfishes, along five principal lines. The test in the living condition is more or less densely covered with spines. The mouth is on the under surface. The anus is either on the top of the test (dorso-central), or somewhere in the median line between the two lower ambulacra. The ambulacra (“a garden path”) are the rows of perforated plates on the upper (abactinal) surface sometimes extending to the lower surface, through which protrude the podia, which in Starfishes are situated in grooves on the lower surface.
Silurian Palaeechinoids.—
The Palaeechinoids are represented in the Silurian of Australia by occasional plates, as at Bowning, New South Wales, and near Kilmore, Victoria, whilst spines are not uncommon in certain Silurian limestones at Tyer’s River, Gippsland.
Carbopermian Palaeechinoids.—
In the Carbopermian of New South Wales, tests ofArchaeocidarishave been recorded, and also a plate of the same genus in the Gympie Beds of Rockhampton, Queensland.
Regular Echinoids.—
The regular Echinoids date from Permian times. They have two vertical rows of plates for each ambulacrum and inter-ambulacrum. The mouth is on the underside, and the anus abactinal (on the upper side) and near the centre.
Fig. 80—CAINOZOIC SEA-URCHINS.A—Cidaris (Leiocidaris) australiae, Duncan sp. Cainozoic (Janjukian). Cape Otway, VictoriaB—Psammechinus woodsi, Laube. Cainozoic (Janjukian). Murray River Cliffs, S. AustraliaC—Fibularia gregata, Tate. Cainozoic (Janjukian). Aldinga, S.A.D—Echinocyamus (Scutellina) patella, Tate sp. Cainozoic (Janjukian). Torquay, VictoriaE—Clypeaster gippslandicus, McCoy. Cainozoic (Janjukian). Bairnsdale, VictoriaF—Studeria elegans, Laube. sp. Cainozoic (Janjukian). Murray River Cliffs, S. Australia.
A—Cidaris (Leiocidaris) australiae, Duncan sp. Cainozoic (Janjukian). Cape Otway, VictoriaB—Psammechinus woodsi, Laube. Cainozoic (Janjukian). Murray River Cliffs, S. AustraliaC—Fibularia gregata, Tate. Cainozoic (Janjukian). Aldinga, S.A.D—Echinocyamus (Scutellina) patella, Tate sp. Cainozoic (Janjukian). Torquay, VictoriaE—Clypeaster gippslandicus, McCoy. Cainozoic (Janjukian). Bairnsdale, VictoriaF—Studeria elegans, Laube. sp. Cainozoic (Janjukian). Murray River Cliffs, S. Australia.
Cainozoic Regular Echinoids.—
In Australasia they make their first appearance in strata of Tertiary age, and some species, asParadoxechinus novus, range through Balcombian strata to Kalimnan in Victoria, or Oligocene to Lower Pliocene, but are more typically Janjukian.Echinus(Psammechinus)woodsi(Fig. 80 B) is common in Janjukian strata in Victoria and South Australia and occurs sparingly in the Kalimnan. Another common form of the regular Echinoids in Southern Australia isCidaris australiae(Fig. 80 A), ranging from Janjukian to Kalimnan, occurring more frequently in the older series. In New Zealand a species ofCidaris(C. striata), is known from theOamaru Series at Brighton. AnEchinusoccurs in the Oamaru Series of Broken River, and two species of that genus in the Wanganui formation of Shakespeare Cliff.Temnechinus macleayanahas been recorded from the Cainozoic (Miocene or Pliocene) of Yule Island, Papua.
Irregular Echinoids.—
The irregular Echinoids are not known before the Upper Cretaceous in Australia, and are very common in the Tertiaries. They are distinguished by the anus (periproct) passing backward from the apex, as compared with the regular forms, and by the elongation of the test and the loss of the strong solid spines, which are replaced by thin, slender hair-like spines. The animal is thus better fitted to burrow through the ooze on which it feeds.
Cretaceous Irregular Echinoids.—
An interesting form,Micraster sweeti, is found in the Upper Cretaceous or Desert Sandstone of Maryborough in Queensland, which reminds one of typical European species of this genus.
Cainozoic Irregular Echinoids.—
Amongst the Australian Cainozoic Echinoids of the irregular type the following may be mentioned. The little subglobular test ofFibularia gregata, andEchinocyamus(Scutellina)patella(Fig. 80 C, D) are Janjukian in age. The largeClypeaster, C. gippslandicus(Fig. 80 E), ranges from the Oligocene to Lower Pliocene in Victoria (Balcombian to Kalimnan), and vies in size, especially in the Janjukian, with some large species like those from Malta and Egypt. This genus includes some of the largest known sea-urchins. The biscuit urchin,Arachnoides (Monostychia)australis, is commonest in the Janjukian, but ranges from Balcombian to Kalimnan. A common urchin from the polyzoal rock of Mt. Gambier isEchinolampas gambierensis, which is also found in the Lower beds of Muddy Creek. A typical Janjukian fossil isDuncaniaster australiae, formerly thought to belong to the Cretaceous genusHolaster. Although found living, the genusLinthiaattained its maximum development both in size and abundance, in Janjukian or Miocene times, as seen inL. gigas(having a length of 71/2inches) andL. mooraboolensis.Echinoneus dennantiis restricted to the Janjukian. Several species ofEupatagusoccur in the Cainozoic or Tertiary beds of South Australia, Victoria and New Zealand;Lovenia forbesi(Fig. 81 C) is common in the Janjukian to Kalimnan, both in Victoria and South Australia. In the latter State also occur the following genera:—Studeria,Cassidulus,Echinolampas,Plesiolampas,Linthia,SchizasterandBrissopsis. In New Zealand the following Cainozoic genera, amongst others of the irregular sea-urchins, may be cited:—Hemipatagus,Brissopsis,Hemiaster, andSchizaster(Fig. 81).
Fig. 81—CAINOZOIC SEA-URCHINS.A—Hemiaster planedeclivis, Gregory. Cainozoic (Janjukian). Morgan, S. AustraliaB—Schizaster sphenoides, T. S. Hall. Cainozoic (Barwonian). Sherbrooke River, VictoriaC—Lovenia forbesi, T. Woods sp. Cainozoic (Janjukian). Murray River Cliffs, S. Australia
A—Hemiaster planedeclivis, Gregory. Cainozoic (Janjukian). Morgan, S. AustraliaB—Schizaster sphenoides, T. S. Hall. Cainozoic (Barwonian). Sherbrooke River, VictoriaC—Lovenia forbesi, T. Woods sp. Cainozoic (Janjukian). Murray River Cliffs, S. Australia
A clypeastroid,Peronella decagonalishas been described from the (?) Lower Pliocene of Papua.
Cainozoic Holothuroidea.—
TheHOLOTHUROIDEA(Sea-Cucumbers) are represented in Australian deposits by a unique example of a dermal spicule of wheel-like form, referred toChiridota, obtained from the Cainozoic (Janjukian) beds of Torquay. This genus is also known from the “calcaire grossier” or Middle Eocene of the Paris Basin, and is found living in all parts of the world.
COMMON OR CHARACTERISTIC FOSSILS OF THE FOREGOING CHAPTER.
CRINOIDS.
(?)Pisocrinus yassensis, Eth. fil. Silurian: New South Wales.
Helicocrinus plumosus, Chapman. Silurian: Victoria.
Botryocrinus longibrachiatus, Chapm. Silurian: Victoria.
Hapalocrinus victoriae, Bather. Silurian: Victoria.
Actinocrinussp. Carboniferous: Queensland.
Cyathocrinussp. Carboniferous: New Zealand.
Phialocrinus konincki, Clarke sp. Carbopermian: New South Wales.
Phialocrinus princeps, Eth. fil. Carbopermian: New South Wales.
Tribrachiocrinus clarkei, McCoy. Carbopermian: New South Wales.
(?)Platycrinussp. Carbopermian: Queensland.
Platycrinussp. Carbopermian: W. Australia.
Isocrinus australis, Moore sp. Cretaceous: Queensland.
Pentacrinus stellatus, Hutton. Miocene: New Zealand, Chatham Ids. and Victoria.
Antedon protomacronema, Chapman. Miocene: Victoria (deep borings).
BLASTOIDS.
(?)Mesoblastus australis, Eth. fil. Carbopermian: Queensland.
STARFISHES.
Palaeaster smythi, McCoy. Silurian: Victoria.
Palaeaster meridionalis, Eth. fil. Silurian: Victoria.
Urasterella selwyni, McCoy. Silurian: Victoria.
Palaeaster giganteus, Eth. fil. Carbopermian (L. Mar. Ser.): New South Wales.
Palaeaster clarkei, de Koninck. Carbopermian (L. and Up. Mar. Ser.): New South Wales.
Pentagonastersp. Miocene: Victoria.
Astropectensp. Miocene: New Zealand.
BRITTLE-STARS.
Protaster brisingoides, Gregory. Silurian: Victoria.
Gregoriura spryi, Chapman. Silurian: Victoria.
Sturtzura leptosomoides, Chapman. Silurian: Victoria.
(?)Sigsbeiasp. Lower Pliocene: Victoria.
ECHINOIDS.
Palaeechinussp. Silurian: Victoria.
(?)Archaeocidaris selwyni, Eth. fil. Carbopermian: New South Wales.
Micraster sweeti, Eth. fil. Cretaceous: Queensland.
Cidaris (Leiocidaris) australiae, Duncan. Miocene and Lower Pliocene: Victoria and S. Australia.
Cidaris striata, Hutton. Miocene: New Zealand.
Echinus (Psammechinus) woodsi, Laube sp. Miocene and L. Pliocene: Victoria and S. Australia.
Temnechinus macleayana, T. Woods. Cainozoic (? Lower Pliocene): Papua.
Fibularia gregata, Tate. Miocene: Victoria and S. Australia.
Echinocyamus (Scutellina) patella, Tate sp. Oligocene to Miocene: Victoria and S. Australia.
Clypeaster gippslandicus, McCoy. Oligocene to L. Pliocene: Victoria.
Arachnoides (Monostychia) australis, Laube sp. Oligocene to L. Pliocene: Victoria and S. Australia.
Echinoneus dennanti, Hall. Miocene: Victoria.
Duncaniaster australiae, Duncan sp. Miocene: Victoria.
Lovenia forbesi, T. Woods sp. Miocene and L. Pliocene: Victoria and S. Australia.
Hemiaster planedeclivis, Gregory. Miocene: Victoria.
HOLOTHURIAN.
Chiridotasp. Miocene: Victoria.
LITERATURE.
CRINOIDS.
Silurian.—Etheridge, R. jnr. Rec. Austr. Mus., vol. V. No. 5, 1904, pp. 287-292 (Pisocrinus). Bather, F. A. Geol. Mag., Dec. XV. vol. IV. 1897, pp. 337-345 (Hapalocrinus). Chapman, F. Proc. R. Soc. Vict., vol. XV. (N.S.), pt. II. 1903, pp. 107-109 (HelicocrinusandBotryocrinus). Bather, F. A. Ottawa Nat., vol. XX. No. 5, 1906, pp. 97, 98.
Carboniferous and Carbopermian.—De Koninck, L. G. Mem. Geol. Surv. New South Wales, Pal. No. 6, 1898, pp. 121-126. Etheridge, R. jnr., in Geol. and Pal. Queensland, 1892, pp. 207-219. Idem, Mem. Geol. Surv. New South Wales, Pal. No. 5, 1892, pp. 75-119.
Cretaceous.—Moore, C. Quart. Journ. Geol. Soc., vol. XXVI. 1870, p. 243. Etheridge, R. jnr., in Geol. and Pal. Queensland, 1892, p. 439 (Isocrinus).
Cainozoic.—Hutton, F. W. Cat. Tert. Moll. and Ech. of New Zealand, 1873, p. 38.
BLASTOIDS.
Carbopermian.—Etheridge, R. jnr., in Geol. and Pal. Queensland, 1892, pp. 210-213. Taylor, T. G. Proc. Linn. Soc. New South Wales, 1908, pp. 54-59 (? Metablastus).
STARFISHES.
Silurian.—McCoy, F. Prod. Pal. Vict., Dec. I., 1874, pp. 41-43. Etheridge, R. jnr. Rec. Austr. Mus., vol. I., No. 10, 1891, pp. 199, 200.
Carboniferous and Carbopermian.—Etheridge, R. jnr. Mem. Geol. Surv. New South Wales, Pal. No. 5, pt. 2, 1892, pp. 70-75. De Koninck, L. G. Ibid., Pal. No. 6, 1898, p. 127.
Cainozoic.—Hall, T. S. Proc. R. Soc., Vict., vol. XV. (N.S.), pt. I. 1902, pp. 81, 82 (Pentagonaster). Hutton, F. W. Cat. Tert. Moll, and Ech. New Zealand, 1873, p. 38.
BRITTLE-STARS.
Silurian.—Gregory, J. W. Geol. Mag., Dec. III. vol. VI. 1889, pp. 24-27. Chapman, F. Proc. R. Soc. Vict., vol. XIX. (N.S.), pt. II. 1907, pp. 21-27.
Cainozoic.—Hall, T. S. Proc. R. Soc. Vict., vol. XV. (N.S.), pt. I. 1902, p. 82 (cf.Sigsbeia).
ECHINOIDS.
Silurian.—Chapman, F. Rec. Geol. Surv. Vict., vol. II. pt. 1, 1907, pp. 77, 78.
Carbopermian.—Etheridge, R. jnr. Mem. Geol. Surv. New South Wales, Pal. No. 5, pt. 2, 1892, pp. 67-69.
Cretaceous.—Etheridge, R. jnr., in Geol. and Pal. Queensland, 1892, pp. 559, 560.
Cainozoic.—T. Woods. Trans. Adelaide Phil. Soc., 1867. Laube, G. C. Sitz, k. k. Ak. Wiss. Wien, vol. LIX. 1869, pp. 183-198. Hutton, F. W. Cat. Tert. Moll, and Ech. New Zealand, 1873, pp. 38-43. Duncan, P. M. Quart. Journ. Geol. Soc., vol. XXXIII. 1877, pp. 42-73. Tate, R. Quart. Journ. Geol. Soc., vol. XXXIII. 1877, pp. 256-258. Idem, Southern Science Record, 1885, p. 4. Idem, Trans. R. Soc. S. Austr., vol. XIV. pt. 2, 1891, pp. 270-282. McCoy, F. Prod. Pal. Vict., Dec. VI. VII. 1879, 1883. Gregory, J. W. Geol. Mag., Dec. III. vol. VII. 1890, pp. 481-492. Ibid., Dec. III. vol. IX. 1892, pp. 433-437. Cotteau, G. H. Mem. Zool. France, vol. II. No. 4, 1889, p. 228; vol. III. No. 5, 1890, pp. 537-550; vol. IV. No. 5, 1891, pp. 620-633. Bittner, A. Sitz. k.k. Ak. Wiss. Wien, 1892, vol. 101, pp. 331-371. Hall, T. S. Proc. Roy. Soc. Vic., vol. XIX. (N.S.), pt. II. 1906, pp. 48, 53. Chapman, F. Proc. Roy. Soc. Vict., vol. XX. (N.S.), pt. II. 1908, pp. 214-218. Pritchard, G. B. ibid., vol. XXI. (N.S.), pt. I. 1908, pp. 392-400.
HOLOTHURIAN.
Cainozoic.—Hall, T. S. Proc, R. Soc. Vict., vol. X. (N.S.), pt. I. 1902, pp. 82, 83.
FOSSIL WORMS, SEA-MATS and LAMP-SHELLS.
T
The first-named group, the ringed worms, belong to the phylum Annelida, so-called because of the ring-like structure of their bodies. The two remaining groups, the Polyzoa or Sea-mats and the Brachiopods or Lamp-shells, are comprised in the phylum Molluscoidea, or mollusc-like animals.
WORMS (Annelida).
Annelida and their Fossil Representatives.—
These animals, owing to the scarcity of hard parts within their bodies, play a rather insignificant role as a fossil group. Worms are laterally symmetrical animals, with a dorsal and a ventral surface. They are segmented, the body being formed of numerous rings. Only those of the Class Chaetopoda (“bristle-feet”) are represented by identifiable fossil remains. Fossil worms, moreover, chiefly belong to the Order Polychaeta (“many bristles”). The horny jaws of these worms are sometimes found in the older rocks and are known as conodonts.
Silurian Conodonts.—
Conodonts belonging to three genera are known from Australia. They are all from the Silurian of the Bowning District, near Yass, New South Wales, and are referred to the generaEunicites,OenonitesandArabellites.
Fig. 82—FOSSIL WORMS.A—Trachyderma crassituba, Chapm, Silurian. South Yarra, Vict.B—Cornulites tasmanicus, Eth. fil. Silurian. Heazlewood, Tas.C—Spirorbis ammonius, M. Edwards, var. truncata, Mid. Devonian. Buchan, VictoriaD—Torlessia mackayi, Bather. ? Trias. Mt. Torlesse, N. Zealand.
A—Trachyderma crassituba, Chapm, Silurian. South Yarra, Vict.B—Cornulites tasmanicus, Eth. fil. Silurian. Heazlewood, Tas.C—Spirorbis ammonius, M. Edwards, var. truncata, Mid. Devonian. Buchan, VictoriaD—Torlessia mackayi, Bather. ? Trias. Mt. Torlesse, N. Zealand.
Palaeozoic Errant Worms.—
The wandering Worms (Polychaeta errantia) are also recognised by their impressions, trails, borings and castings. Burrows formed by these worms are seen inArenicolites, found in the Silurian sandstone of New South Wales, near Yass, and in the Carbopermian (Gympie Series) near Rockhampton, Queensland. The membranous-lined burrows ofTrachyderma(T. crassituba), occur in some abundance in the Silurian mudstones in the neighbourhood of Melbourne,Victoria (Fig. 82 A). The genusTrachydermais common also to Great Britain and Burmah, in beds of the same age.
Worm Tracks.—
Some of the curious markings on the Carboniferous sandstone of Mansfield, Victoria, may be due to worm trails and castings, especially since they are associated with sun-cracks and ripple-marks.
Sedentary Worms.—
The sedentary or tube-making Worms (Polychaeta tubicola) are represented by numerous forms. The long conical tube ofCornulites tasmanicusis recorded from the Silurian of Zeehan, Tasmania (Fig. 82 B).Spirorbisoccurs in the Middle Devonian of Victoria (Fig. 82 C), and W. Australia, and also in the Carbopermian of W. Australia.Torlessiais found in the Trias or Lower Jurassic of the province of Canterbury, New Zealand (Fig. 82 D). The genusSerpulais widely distributed, occurring in the Carbopermian (Upper Jurassic Series), near East Maitland, New South Wales (S. testatrix), in the Jurassic of W. Australia (S. conformis), in the Lower Cretaceous of Wollumbilla, Queensland (S. intestinalis), and the Darling River, north west of New South Wales, (S. subtrachinus), as well as in Cainozoic deposits in Victoria (S. ouyenensis).Ditrupais very abundant in some shelly deposits of Janjukian age in Victoria.
MOLLUSCOIDEA.
The Sea-mats (Polyzoa) and the Lamp-shells (Brachiopoda) constitute a natural group, the MOLLUSCOIDEA, which, although unlike in outwardform, have several physiological structures in common. The respiratory organs lie in front of the mouth, and are in the form of fleshy tentacles or spiral appendages. These animals are more nearly allied to the worms than to the molluscs.
POLYZOA.
Characters of Polyzoa.—
These are almost exclusively marine forms, and are important as fossils. They form colonies (polypary or zoarium), and by their branching, foliaceous or tufty growth resemble sea-weeds. The cells in which the separate zoöids lived have peculiar characters of their own, which serve to distinguish the different genera.
Subdivisions of Polyzoa.—
Polyzoa are divided into the Sub-classes Phylactolaemata, in which the mouth of the zoöid has a lip, and the series of tentacles is horse-shoe shaped; and the Gymnolaemata, in which there is no lip to the mouth, and the tentacles form a complete circle. The first group forms its polypary of soft or horny material, which is not preserved fossil. The latter has a calcareous polypary, and is of much importance as a fossil group. This latter sub-class is further subdivided into the following Orders, viz.:—Trepostomata (“turned mouths”), Cryptostomata (“hidden mouths”), Cyclostomata (“round mouths”), and Cheilostomata (“lip mouths” furnished with a moveable operculum).
Trepostomata (Palaeozoic).—
The Order Trepostomata may include some genera asMonticuliporaandFistulipora, previously referredto under the corals. They become extinct after Permian times.Fistuliporaoccurs in certain Gippsland limestones.
Fig. 83—PALAEOZOIC POLYZOA.A—Fenestella margaritifera, Chapm. Silurian. Near Yering, Vict.B—Polypora australis, Hinde. Carbopermian. Gascoyne River, Western AustraliaC—Rhombopora tenuis, Hinde. Carbopermian. Gascoyne River, Western AustraliaD—Protoretepora ampla, Lonsdale sp. Carbopermian. N.S.W.
A—Fenestella margaritifera, Chapm. Silurian. Near Yering, Vict.B—Polypora australis, Hinde. Carbopermian. Gascoyne River, Western AustraliaC—Rhombopora tenuis, Hinde. Carbopermian. Gascoyne River, Western AustraliaD—Protoretepora ampla, Lonsdale sp. Carbopermian. N.S.W.
Cryptostomata (Palaeozoic).—
In the order Cryptostomata we have the genusRhomboporawith its long, slender branches, which occurs in the Silurian of Victoria and the Carbopermian of Queensland and W. Australia (Fig. 83 C). Of this order a very important Australian genus isFenestella, the funnel-shaped zoaria of which are found in the Silurian of Victoria and New South Wales, and also in the Carboniferous of the latter State.Fenestellaalso occurs in the Carbopermian ofW. Australia and Tasmania (Fig. 83 A). Accompanying the remains ofFenestellain the Carbopermian rocks, and closely related to it, are found the generaProtoreteporaandPolypora(Fig. 83 B, D).
Polyzoa have been noticed in Jurassic rocks in W. Australia, but no species have been described.
Fig. 84—CAINOZOIC POLYZOA.A—Lichenopora australis, MacGillivray. Balcombian. Hamilton, VictoriaB—Heteropora pisiformis, MacGillivray. Janjukian. Moorabool, VictoriaC—Cellaria australis, MacGillivray. Balcombian. Hamilton, Vict.D—Selenaria cupola, T. Woods sp. Balcombian. Hamilton, Vict.E—Lepralia elongata, MacGill. Balcombian. Hamilton, Victoria
A—Lichenopora australis, MacGillivray. Balcombian. Hamilton, VictoriaB—Heteropora pisiformis, MacGillivray. Janjukian. Moorabool, VictoriaC—Cellaria australis, MacGillivray. Balcombian. Hamilton, Vict.D—Selenaria cupola, T. Woods sp. Balcombian. Hamilton, Vict.E—Lepralia elongata, MacGill. Balcombian. Hamilton, Victoria
Cheilostomata (Cretaceous).—
Species of the genera (?)Membraniporaand (?)Lepralia, belonging to the Cheilostomata, have been described from the Lower Cretaceous of the Darling River, New South Wales, and Wollumbilla, Queensland, respectively.
Cainozoic Polyzoa.—
A very large number of genera of the Polyzoa have been described from the Tertiary strata of South Australia and Victoria. Some of the principal of these areCrisia,Idmonea,Stomatopora,Lichenopora,Hornera,EntalophoraandHeteroporaof the order Cyclostomata; andCatenicella,Cellaria,Membranipora,Lunulites,Selenaria,Macropora,Tessarodoma,Adeona,Lepralia,Bipora,Smittia,Porina,CelleporaandReteporaof the order Cheilostomata. Many of these genera, and not a few Australian species, are found also in the Cainozoic or Tertiary beds of Orakei Bay, New Zealand (Fig. 84).
BRACHIOPODA (Lamp-shells).
Brachiopods: Their Structure.—
These are marine animals, and are enclosed in a bivalved shell. They differ, however, from true bivalves (Pelecypoda) in having the shell on the back and front of the body, instead of on each side as in the bivalved mollusca. Each valve is equilateral, but the valves differ from one another in that one is larger and generally serves to attach the animal to rocks and other objects of support by a stalk or pedicle. Thus the larger valve is called the pedicle valve and the smaller, on account of its bearing the calcareous supports for the brachia or arms, the brachial valve. Generally speaking, the shell of the valve is penetrated by numerous canals, which give the shell a punctate appearance. Some brachiopod shells, asAtrypaandRhynchonella, are, however, devoid of these.