G8 P. M. DUNCAN ON THE ECECINODEEMATA OF THE the Australian deposits ; and there is a Recent form, Eupatagus Valenciennesi, Agassiz, in the Australian seas. Two of the species are described in this communication ; and the others are to be found in Laube's essay (op. cit. p. 195). Eupatagus rotundus, mihi, is an exceedingly beautiful species and is a large form. E. Laubei is smaller, and with its small tubercles, petals of equal size, and the forward peristome is distinguished from all others. The genus is well represented in the Eocene, especially in the French and Indian Nummulitic. It occurs in the European Mid Tertiaries also. Lovenia Foebesi, syn. Hemipatagus Forbesi, Woods and Duncan. The beautiful fossils from Mordialloc (which have all their orna- mentation perfect) prove that Hemipatagus is really a form of Lovenia. There is an internal fasciole and a subanal one also. The descriptions in the part of this paper which refers to the species are so full that it i3 not necessary to recapitulate here. The genus Lovenia (Hemipatagus included) is of some antiquity, as species have been found in the Nummulitic of North Africa, the Crimea, and Sinai, in the Miocene of Corsica, and of the Bavarian Alps. It is found in the Pliocene of Java and in the Cainozoic deposits of New Zealand. It is, as Lovenia, a Recent genus of great beauty ; and there are three species — one from the gulf of California, one from China, Japan, and the Sandwich Islands, and a third from the Red Sea, the Philippines, and the Australian coast. A great Schizaster is found in the Adelaide Tertiaries, and it is undistinguishable from Schizaster ventricosus of the Australian fauna. The Micraster noticed by Laube and Etheridge is not unlike some European forms, and has a most Cretaceous appearance ; but in a specimen in the British Museum there are faint indications of a lateral fasciole. The new genus Megalaster is represented by one species ; it re- calls the Cardiasters, but there are generic differences in the relative size of the pores of the poriferous zones, and in the absence of fascioles in the new form. Nevertheless the position of the mouth and the general shape recall the Cardiasters described by Stoliczka in his monograph on the Echinodermata of the Cretaceous deposits of Southern India. The size of the species is great, and perhaps is only surpassed by Plagionotus at the present day. It is probably an extinct form, and was a remnant of the Cretaceous fauna which died out in the Miocene. VII. Conclusions. It will have been noticed from the description of the species, and from the summary just given of their peculiarities and alliances, that the Australian Cainozoic Echini are remarkable as a fauna. A portion of the assemblage looks very recent ; another appears as if it had been selected from distant recent faunas ; and a third has an evident affinity to that of the present Australian seas. Then the presence of such genera as TemnecJiinus, Echinolampas, Pygo-
Page:Quarterly Journal of the Geological Society of London, vol. 33.djvu/98
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P. M. DUNCAN ON THE ECHINODERMATA OF THE