604 MR. U. I. POCOCK ON THE 



By their feet the genera may be distinguished as follows : — 



a. Feet fossorial with digits sbort, claws long, blunt and 

 slightly curved, and the granulai' pads but little differen- 

 tiated ; hallux short, its distal phalange reduced to a button- 

 like excrescence on the shortened lobe, which, however, still 

 retains the capacitj' for movement in the opposable plane ... Phascolomys. 

 a'. Feet scansorial and prehensile, with longer digits and sharp, 

 curved claws, and differentiated pads ; hallux very large and 

 opposable, with well-developed terminal phalange. 

 h. Fore foot as large as hind foot, with comparatively long and 

 narrow sole ; the inner lobe of the plantar pad small aud 

 attached to the base of the second digit, which is separated 

 by a long space from the third; the inner lobe of the 

 carpal pad small, isolated from the outer and attached to 

 the base of the first digit (pollex) ; second and thi-d digits 



of hind foot comparatively large, strongly prehensile Phascolarctos. 



hi. Fore foot smaller than hind foot, with shorter, broader sole ; 



the inner lobe of the plantar pad large, in contact, or 



nearly so, with the rest of the pad and fused into one mass 



with the inner lobe of the carpal pad, there being no differ- 



tiated pad at the base of the first digit (pollex) ; second 



and third digits of hind foot short, weakly prehensile. 



c. A comparatively long space between the third and second 



digits of the foi-e foot, the second acting in unison with 



the first like a double opposable pollex ; pads striated ... JPlialanger and 



Pseud ocli irtis^ 

 ci. The five digits of the fore foot evenly spaced, the second 

 in no respect opposable to the next, and the first or pollex 

 only slightly so; pads granular Triclwsurtis. 



The Pouch. — I have seen no fresh female examples of Phalanger 

 and Pseudochirus. 



[n Trichosurus the poucli, as in Macropus, is deeper than 

 wide its orifice has a well-developed lateral and posterior rim 

 hut no overhanging anterior rim ; it therefore laoks forwards * ; 

 and in the specimen examined there were only two teats, 

 not four, as stated by Winge to be characteristic of the 

 Phalangeridje. 



In Phascolomys the pouch is a little wider than long, being 

 deeper laterally, especially anteriorly, than behind or mesially in 

 front and a little deeper behind than mesially in front, the 

 muscular rim overhanging the cavity all round ; and there is a 

 single pair of teats. 



In Phascolarctos the pouch, as recorded by Forbes, is much 

 wider than long, being extended, gradually narrowing as it goes, 

 along the depression between the muscles of the thigh and 

 abdomen nearly as far as the edge of the flap of integument 

 ioinino- the hind leg to the body, its width being about three 

 times its leniith. The orifice looks slightly backwards, the 

 muscular rim overhanging the cavity laterally and to a slight 

 extent in the middle line in front, but ceasing on each side close 

 to the position of the single teat. The orifice therefore looks 

 backwards. 



* In his volume on Marsupials (Allen's Naturalists' Librarj', p. 76, 1894), 

 Lydekker wrongly states that the orifice of the pouch is directed backwards in 

 Phalangeridie. 



