KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 60- N:0 6- 45 



The underparts of the body are fairly variable, in some of the specimens 

 blackish slaty, while in others tinged with buffy ochraceous. The unicoloured tails 

 are dark brown throughout their whole length, and fairly well clad with hairs. The 

 fur is almost without spines and grizzled black and rufous above. The hands and 

 feet are whitish and the metapodials in some of the specimens dark brown along the 

 centre. 



43. Hseromys sp. 



Xo. 82. $ juv. Mara, Eastern Borneo(?) 8 ,<3 1914. Head and body: 91 mm. Tail: 85 mm. Hindfoot: 

 2b mm. Ear: 13 mm. 



The specimen is too young to be determined, but must certainly be referred 

 to the genus Hceromys as defined by Thomas (Ann. & Mag. Nat. Hist., 8 ser., vol. 

 VII, 1911, p. 207). The members of this genus have a skull similar to that of 

 Chiropodomys, but the molars are without the postero-internal cusp, thus resembling 

 the teeth of the rattus-group. The general aspect of the skull is very short and 

 broad, being especially evident in the broad and rounded braincase. 



44. Acanthion mulleri Jentink. 



Xotes Leyden Mus., vol. 1, 1879 ; p. 89. 

 One skull without skin, Toembang Maroewe. Central Borneo, Sept. 1915. 



This single skull has belonged to an immature animal, the skin of which has 

 been löst. Two species of Porcupines occur in Borneo viz. Acanthion crassispinis 

 Gunth. and Acanthion mulleri Jent. Of the former there is a good plate accom- 

 paning the original description (Proc. Zool. Soc. London, 1876, p. 737) and the ani- 

 mal is characterized by its short nasals which are shorter than the frontals. In A. 

 mulleri on the contrary, the nasals are longer than the frontals, thus resembling the 

 species found it the Malay Peninsula and adjacent countries viz. Acanthion orachyurus 

 Linn. (syn. A. grotet Gray) and Acanthion klossi Thos. 



According to Hose (Mammals of Borneo, London 1893) A. mulleri may be disting - 

 uished from A. crassispinis by having a black belly and by somewhat different caudal 

 quills. In Gunther's original description of A. crassispinis nothing is remarked about 

 the colour of the belly, and Lyon in his »Notes on Malayan Porcupines» (Proc. U. S. 

 Nat. Mus., vol. 32, 1907, p. 581) states that »in all probability A. crassispinis has 

 a dark belly». I am not able to confirm if Lyon's statement is correct or not on 

 account of the lack of material, but the skulls of the two forms are certainly different 

 and therefore it seems that Jentink's A. mulleri certainly is a good species. 



Skull measurements : Greatest length of skull: 115,6; length from condylus to 

 gnathion: 108,o; basicranial length of skull: 95,3: occipitonasal length: 114,8: zygo- 



