MAMMALIA. 13 



naked streaks down the centre of the forehead, both which characters are well 

 defined in M. Buffon's figures (Hist. Nat. xv. t. 12). 



Buftbn, Geoffroy, and Kuhl described the hair on the top of the head as white : 

 one of the specimens, which has been for some years in the collection of the 

 British Museum, and much exposed to the light, is of a yellowish white colour. 

 But the fresh specimens, differing from the other in no other particular, have the 

 hair of this part of a bright yellow colour, as they are described by Kuhl in his 

 P. ochrocephala ; so that I suspect the description of one species was taken from 

 a bleached, and the other from a fresh specimen. 



A few of the hairs on the side of the neck, the shoulders, the fore-arms, and 

 the hinder edge of the thigh are of a brownish colour at the tip, and have a 

 withered appearance ; and some of the hairs of the tail are of a brown colour, 

 and have the same appearance for the greater part of their length : but these 

 hairs scarcely alter the general colour of the animal, which is of a brownish black 

 tinge, quite different from the grisled black and brown appearance of the next 

 species, and our specimen scarcely justifies the account of the colour of the hair 

 given by my very accurate friend M. Kuhl. 



I strongly suspect that the P. inusta of Spix must have been taken from 

 a specimen of this species, though he does not represent the bald streak on 

 the head, and describes the hands as yellowish : but in his description of 

 P. hirsuta, (which M. Temminck suspects is the same as P. inusta,) he observes, 

 that the hands of the young of that species differ from those of the adult in 

 being whitish, while in the full grown they are yellowish black. The same 

 change may take place in P. leucocephala, which does not appear to be a rare 

 species. 



The whiskered Yarke. — Pithecia Pogonias. 



Plate II. — Animal. 

 Pithecia Pogonias, Gray, Ann. and Mag. Nat. Hist. 18-12, 256. 



The head covered with hair ; face surrounded with black hairs, with yellow tips ; forehead, a 

 line up the vertex, and cheeks covered with long close-set yellow hair; hair of the 

 back and limbs blackish, with a broad white subterminal ring, of the feet short and black. 



Inhab. Tropical America. 



This species is so abundant in the London collections, that one can scarcely 

 conceive that it is not a described species ; but, though it agrees with the Saki of 



e 



