146 Mr. O. Thomas on a new Papuan Phalanger. 



XVII. — Description of a nao Pa^nian Phalanger. 

 By Oldfield Thomas. 



PseudocTiirus Forhesi, sp. n. 



Externally almost precisely similar in size and colour to 

 Ps. cayiescenSy Waterli. *, but with no dark central streak on 

 the head, with a large black patch in front of as well as be- 

 hind the ear, with the ears themselves more thickly haired 

 and surrounded by tufts of long soft hairs, and with the tail 

 much more thinly haired, especially on its distal half. 



Skull differing from tliat of Ps. canescens by its smaller and 

 lighter build, flattened instead of vaulted nasals, more concave 

 forehead, stronger supraorbital ridges, forming rudimentary 

 postorbital processes, corresponding to which there is a marked 

 prominence on the upperside of the malar bone. 



Teeth, on the whole, small and light. Molars of about the 

 same size as in Ps. Bernstei'iii, but the anterior teeth remai'k- 

 ably reduced, the incisors, canine, and posterior premolars very 

 small, while the third incisor and first premolar are altogether 

 suppressed, the upper dental formula being therefore 



I. 2,C. 1,PM. 2,M.4,x2 = 18, 



a formula quite unique in the family. 



Below, the rudimentary teeth between i.^ and pm.^ are 

 wholly absent in one jaw, while in the other there is the 

 alveolus from which a single minute tooth has been lost. 



Dimensions of the type, an adult male (skin) : — 



Head and body (c.) 280 millim., tail 230, Iiind foot 30, 

 ear (c.) 13, naked part of tail (c.) 100. 



Skull: basal length 47*7 millim., greatest breadth 30'0; 

 length of first three molars 8*8, vertical length of i.^ 3*3. 



Habitat. Sogere, Astrolabe Mountains, South-east New 

 Guinea, 2000 feet altitude. Collected by H. O. Forbes, Esq. 



The discovery of this highly interesting species is one of 

 the results of Mr. H. O. Forbes's recent expedition to New 

 Guinea, and I have very great pleasure in connecting his 

 name with it. 



Besides Ps. canescens the only other species allied to Ps. 

 Forhesi is Ps. Schlegeli, Jent. f, which may, however, be 

 readily distinguished from it by its wholly unstriped body, 

 hairy underside of tail, vaulted nasals, more convex forehead, 

 and very markedly larger teeth, among which i.^ and ^:)ot.^ are 

 of course present. 



Of this small group of Phalangers only five specimens are 



* Figured by Ilombron and Jacquinot, Voy. Pole Sud, Zool. Atl. 

 pi. xix .(1842-53). ( = Ps. Bernsteini, Schl., figured by Peters and Doria, 

 Ann. Mus. Genov. xvi. pi. xii. 1880.) 



t Notes Leyd. Mus. vi. p. 110 (1884). 



