OCR Text |
Show 194 MR. J. W. CLARK ON A [Mar. 18, should have considered that he was right in so doing ; but as MM. Quoy and Gaimard thought proper to sink their own individuality in that of Peron, it seems to me that we have no choice left but to accept the species with Peron's name attached to it, more especially as they brought home a skin and skull, both of which are figured in their work, and are now in the Museum of the Jardin des Plantes. These specimens ought, I submit, to be considered as the type of the species; and it was after a careful examination of them that I ventured on a former occasion to mention Otaria cinerea as one of the four distinct species of Otaria inhabiting the Australian coast (P.Z.S. 1875, p. 676). I have taken the skulls now before us to Paris and compared them with the type of Otaria cinerea, and there can be no doubt that they should all be referred to that species. The type skull is of an animal not quite adult, stated by the authors to he a male ; it is in excellent condition ; and the teeth have never been displaced. It is 10| inches long by 6^ inches broad across the zygomatic processes. The form of the nasals and of the orbital process of the frontal will be better understood from the figure of the same bones here given (fig. 3, p. 191) than from any description. Immediately behind these processes the skull contracts suddenly, so that while the width across the processes is 2j inches, that across the narrowest portion of the skull behind them, close to the brain-case, is only lj> inch. The dental series is, as usual:- 6 1-1 6-6_Q In the molar teeth the " cingulum " is very feebly developed ; and each tooth, both in the upper and lower jaw, has a posterior and an anterior cusp, characters which are very useful in separating this species from that which appears to be most nearly allied to it, Otaria albicollis, Peron, = 0. australis, Quoy and Gaimard, of which there is a fine series in the same museum. The opening of the palate is long and V-shaped (fig. 4, p. 192), and the auditory bulla is prolonged posteriorly into a peg-like process (figs. 2 & 4, pp. 190, 192). Of the skulls before us, the largest (figs. 1, 2) undoubtedly belongs to a full-grown male. It is llf inches long by 7k broad, measured across the zygomatic arches. The occipital and sagittal crests, and the parietal processes, are all fully developed, and the nasals are nearly obliterated by anchylosis with the premaxilla. It is, however, easy to see that the form of these bones, and of the upper part of the skull generally, is identical with the female skull (fig. 5, p. 193), which has been already referred to as closely resembling the type specimen. The palate in the male skull (fig. 2) is more elongated than in either of the others or in the type specimen ; but, useful as the form of this part is for specific determination, it must be remembered that it is subject to remarkable individual variations, the neglect of which has led to a needless multiplication of species1. In order to show 1 I hope my friend Professor Turner will forgive me if I quote his Euotaria schisthyperbcs (Journ. Anat. 1868, p. 113) as an instance of this. I feel tolerably sure that the skull so named should be referred to Otaria pusilla., |