Zoological Society. 213 



streak across the shoulders ; the Hylomys are uniform dark- coloured ; 

 the Dendrogale and Ptilocercus have no shoulder-streak, but a dark 

 streak on the side of the face inclosing the eyes ; the former having 

 a white spot on the forehead not observable in the latter. 



At first sight Ptilocercus has much the appearance of a marsupial 

 animal allied to Cuscus, but this resemblance proves to be only in 

 the mere external form, when the characters are examined, as for 

 example, it wants the large great-toe of that group. 



The skulls of Tupaia and Ptilocercus have a considerable resem- 

 blance to that of the Lemuridce, and particularly in having the orbits 

 entire. The Tupaia are peculiar in having a large elongated aperture 

 on the hinder part of the middle of the zygomatic arch, while the 

 Ptilocercus has only a small round perforation in the front part of 

 the middle of the same part, which is probably the analogue of the 

 hole in the former genus. 



Ptilocercus, n. g. 



Head moderately tapering; whiskers elongated, rather rigid. Ears 

 moderate, naked, exposed. Body slender, fur soft. Limbs moderately 

 elongated, nearly equal. Toes 5*5, rather compressed, free. Thumb 

 moderate, like the toes, but shorter. Claws short, compressed, tri- 

 angular, acute. Tail elongate, cylindrical, hairy quite at the base, then 

 naked, covered with rings of square, broad, adpressed scales and short 

 scattered hairs, and the hinder third with a series of elongate hairs, 

 forming a barb on each side. Skull conical ; face rather short. 



Cutting teeth ' ' ' : upper elongate, far apart, rather curved; lower 



shelving, front pair conical, small, shorter than the middle pair, 

 which are elongate, curved, acute ; the hinder smallest and shortest. 



Canines none. Grinders j~£ the front 3 . 3 in each jaw, small ; 



the hinder 4 . 4 large, square, acutely tubercular. 



The skull is shorter, broader, and the face less elongated than that 

 of the different species of Tupaia, and it differs from them in the two 

 front teeth of the lower jaw being smaller and shorter than the suc- 

 ceeding one, while in all the species of Tupaia (including the genus 

 Dendrogale) figured by Temminck, the four front teeth of the lower 

 jaw are equally elongated. 



The hinder cutting tooth in the upper jaw is placed on the suture 

 of the intermaxillary (and hence may be a true canine) and not in 

 front of the suture of the intermaxillary, as is the case with the skull 

 of Tupaia tana and T.ferruginea in the British Museum collection. 



Ptilocercus Lowii. 



Blackish-brown, very minutely grizzled with the yellowish tips of 

 the hairs ; lips, lower part of cheeks, chin, and beneath yellowish : 

 sides of the face inclosing the eyes black. Tail black ; barbs white, 

 except a few hairs near the scaly part, which are black. 



Length, 5| inches; tail, 6£; hind-foot, 1. Skull: length, 1"4"'; 

 tooth line, 7i'"; of face, 5"'; of zygomatic arch, 7f"; width at zy- 

 gomatic arch, 9^"'; at temples, 6±'" ; between orbits, 3 J'". 



Inhab. Borneo, Sarawak. 



