21G 
MACRO PODID/E. 
These dimensions show the extreme of variation which I 
have observed in the skulls of numerous specimens of the 
Rat-Kangaroo under consideration : they also teach us that, 
unlike the true Kangaroos, there is not any marked dilference 
in the size of the cranium of the two sexes. As regards the 
fifth and sixth columns, it will be perceived that the two 
skulls, the dimensions of which are there given, have the 
nasal bones rather broader behind than the other skulls, and 
the premolar tootli is a triHe longer from front to back. The 
animal from which the skull of the sixth column is taken was 
not sent home ; that belonging to the skull of the fifth 
column is in the museum of the Zoological Society, and is 
the specimen figured in “ Marsupiulia” (Plate 1G). Of this 
specimen (which is a male), the liubitat is unfortunately not 
known : in its colouring it is, in some respects, intermediate 
between the B. penicillata and B. Oyilbyi , having the rich 
rusty brown tail of the latter, but the tarsi paler, though 
considerably suffused with rust colour, especially about the 
heel. Its dimensions are given below, in column A. 
The dimensions of a skull given in the seventh column 
are those of a male specimen of Hyps, penicillatus in the 
British Museum, from Liverpool Plains, New South Wales, 
(specimen b of the Museum Catalogue). This individual 
agrees closely with the original specimen in the Zoological 
Society's Museum ; hut I do not perceive any yellow tint on 
the under parts of the body, which are here impure white; 
and on the chest is a patch of white hairs which ore uniform 
throughout, having no grey at the root ns usual. Its 
dimensions are given in column 13. 
In two specimens of B. Ogilbyi , in Mr. Gould’s Collection, 
from the vicinity of York, Western Australia, the general 
colouring of the fur was brown, but freely pencilled with 
yellowish white; the cheeks and sides of the body distinctly 
suffused with yellow ; the under parts yellow*white ; cars 
