| OCR Text |
Show 1867.] MR. SCLATER ON ADDITIONS TO THE MENAGERIE. 815 The skull separates the animal individually from P. wombat by the characters previously defined ; but these, the later examination proves, are occasionally inconstant, so that the more unstable ground of size bas to be called into aid. Hence P. platyrhinus does not present such permanent broadly marked osteological characters as would afford the paleontologist arguments for holding it up as a specific type. But when the external characters are brought to bear upon the question along with the osteological variations, most naturalists, as species are at present defined, would admit its separation. Analogous instances occur in the Felidce. Many other examples might be given where, although it is difficult rigidly to define differential characters from the skeleton alone, yet zoologists freely admit specific distinction. P. latifrons is clearly specifically different, and may be generically so, although I have only given it the rank of a subgenus. This last animal possesses many peculiarities, and fills up a gap between the Wombats and other genera of the Marsupials. In the excellent volume on the Marsupiata by Waterhouse*, that author is " inclined to regard the genus Phascolomys as presenting an aberrant form only of the Phalangistidee." The present observations concerning the skeleton of the genus Phascolomys lend weight to his opinion; for in a number of points P. latifrons bears affinities to the Phascolarctus cinereus, and in P. platyrhinus we even find a peculiarity in the number of sternal bones belonging to the genus Petaurus. If we admit a general diminution in the size of recent Mammalia, compared with many of the old fossil forms, and wonder how such alteration in magnitude and proportions has been brought about, whether by natural selection or otherwise, we have in these W o m bats a curious illustration of the phenomenon. The postpliocene of Australia gives up its Phascolomys magnus, a gigantic Wombat. In some beds of the same deposits comes P. platyrhinus, which seemingly yet lives ; lastly, we find now predominant the but slightly altered and comparatively diminutive form P. wombat. November 14, 1867. George Busk, Esq., F.R.S., V.P., in the Chair. Mr. P. L. Sclater, Secretary to the Society, called attention to the following noticeable additions to the Menagerie, which had been made during the past summer :- 1. A n adult specimen of the Golden Tiger-cat of Sumatra (Felis * Nat. Hist. Mammalia, vol. i. (1846), p. 16. |
