186/.] 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 has 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 Felidee. Many other examples 

 might be given where, although it is difficult rigidly to define dif- 

 ferential 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 Phalangistidce." The present obser- 

 vations 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 Wom- 

 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. 

 jilatyrhinus, which seemingly yet lives ; lastly, we find now predo- 

 minant the but slightly altered and comparatively diminutive form 

 P. loomhat. 



November 14, 186/. 

 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. An adult specimen of the Golden Tiger-cat of Sumatra (Felis 

 * Nat. Hist. Mammalia, vol. i. (184G), p. 10. 



