1867.] MR. SCLATER ON ADDITIONS TO THE MENAGERIE. 815 



The skull separates the animal individually from P. wombat bv 

 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. ^ 



^^WQF.platyrhinus does not present such permanent broadly 

 rnarked osteolog,cal 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 



deWl^wn ^rfT\ ™°'' naturalists, as species are at present 

 denned, would admit its separation. 



Analogous instances occur in the Felid<B. 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. * ^ 



«n ^:\lf^T\ t ^^^""'^ specifically different, and may be generically 

 so, although I have only given it the rank of a subgenus. ^ 



lliis 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 "niclined to regard the ^..J masllomys as ^ resen ng 

 an aberrant form only of the Phalangistidcer The present obser- 

 weiir.nT''™-"^ the skeleton of the genus Phascolomys lend 



aSkil to'thTpT"' f 'f ' ""°^'^''' °^ P''^^^^ ^- ^«^^>«^* bears 

 efenfinri « ^^' ^^^'''^"^'=1^^^ cmereus, and in P. platyrhinus we 

 even find a peculiarity in the number of sternal bones belonging to 

 the genus Petanrus. ^ ° 



If we admit a general diminution in the size of recent Mammalia 

 compared with many of the old fossil forms, and wonder how sud! 

 alteration in magnitude and proportions has been brought abou 

 whether by natural selection or otherwise, we have in thfse Won : 

 bat^ a curious illustration of the phenomenon. 



Ihe postpliocene of Australia gives up its Phascolomys maanus 

 a g gantic Wombat. In some beds of the same deposits^ co^nfsP 



pZnbat ^ ^ ''^ '"'^ comparatively diminutivi form 



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 

 fo lowing noticeable additions to the Menagerie, which had b en 

 made during the past summer :— 



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

 * Nat. Hist. Mammalia, vol. i. (1846), p. IG. 



