594 MR. R. I. POCOCK ON THE 



Weber. Family PHALANGERIDJi:. 



Subf'amilj' Maceopodinje {3Iacrojoi(s, Dendrolagus, Fotorous, 

 Settongia, etc.). 

 „ HXPSIPEYMNODONTINJJ {Hypsiprymnodoii). 



„ Phalangeein^ {Tarsipes , Plialanger, Trichosurus, 



Fseudochirus, Petauroides). 

 Family PHASCOLARCTID^ {PJiascolcirctos, Phascolomys). 



External Characters. 



The Bhinarium. — In Trichosurus the rhinarium is Inrge, naked, 

 and eoQvex above; the infranarial portions are complete laterally 

 and narrow; there is a median groove extending between the 

 nostrils on to the philtrum, which is divided into two narrow 

 strips, with a, little process, overlying the gum between the median 

 incisors, at the apex of the angular excision above. The nostrils 

 are of the typical form, consisting of a rounded orifice in front, 

 moderately widely separated from its fellow of the opposite side, 

 and of a lateral and posterior narrow slit. 



In Phalanger the rhinarium is in a general way similar to that 

 of Trichosuribs, but the nostrils are more widely separated, the 

 infranarial portion is deeper in front, and the philtrum is ex- 

 ceedingly wide, and, although gradually nai-rowed below, is quite 

 wide where it terminates on the edge of the upper lip. There is, 

 moreover, no angular excision such as is seen in Trichosurus, but 

 the median groove broadens below, its floor terminating in a. 

 median process which projects at least as low as the lateral 

 portions of the philtrum. 



In Pseudochirus the rhinai'ium is more like that of Tricho- 

 surus, but the infranarial portions are wider in front, with the 

 inferior edge more steeply inclined ; the median groove is con- 

 tinued between the nostrils to the summit of tlie rhinarium ; and 

 the inferior portion of the philtrum is quite narrow, with a small 

 median notch. 



In Phascolarctos the nose is widely different. The muzzle is 

 abruptly sloped downwards about an inch above the nostrils, and 

 the whole of this inclined area is covered with very fine, short,, 

 scattered hairs, leaving a narrow, naked, thickened rim round the 

 nostrils. Thus there is no true rhinarium. The nostrils them- 

 selves are also peculiar. Each consists of an ovally elongated 

 valvular orifice, with a thickened superior and lateral rim, but 

 with the inferior rim hardly defined from the upper lip ; all 

 trace of differentiation into lateral slit and anterior orifice has 

 disappeared ; the septum is very nairow, and is continued in- 

 feriorly between the two halves of the upper lip, ending below in 

 a process over the gum between the median incisors. 



In Phascolomys ursinus * the rhinarium is quite unlike that of 

 Phascolarctos, and resembles, broadly speaking, the rhinarium 



* The rhinarium of Lasiorhinus latifrons, the hairy-nosed Wombat, which 

 should, I think, rank as a di.stinct jrenus, is unknown to me except from descriptions 

 and a dried skin. It appears to differ solely from that of Phascolomys in being- 

 covered with short hair, the nostrils being normally termed. 



