QUADRUMANA. 71 



NocTHORus, Fred. Cuv. Nyctipithecus, Spix. Improperly- 

 called Aotus by lUiger. 



Only differs from the Sagouins in its great nocturnal eyes, and in 

 the ears, which are partly hidden under the hair. One species only 

 is known. 



Nocth. trivirgata^ Fred. Cuv., Mammif. ; Nyctipith. vociferans, 

 Spix, pi. 18. (The Douroucouli.) Ash-coloured above, yel- 

 lowish beneath; a black vertical line on the middle of the fore- 

 head, and one on each temple. It is a nocturnal animal of 

 South America.(l) 

 They are all from Guiana or Brazil. 



OuisTiTis. Hapale, Illig. Arctopithecus, GeofF. 



A small genus, similar to the Sakis, and for along time confounded 

 with them in the great genus of monkeys. In fact, like the genera- 

 lity of the American monkeys, they have the head round; visage 

 flat; nostrils lateral; buttocks hairy; no cheek-pouches, and, like the 

 Sakis in particular, the tail not prehensile. They have only, how- 

 ever, twenty grinders, like the monkeys of the eastern continent; all 

 their nails are compressed and pointed, those of the hind thumbs 

 excepted, while their anterior ones are so slightly separated from 

 the fingers, that it is with hesitation we assign to them the name of 

 quadrumana. They are pretty little creatures, of agreeable forms, 

 and easily tamed. 



M. Geoffroy distinguishes the Oicistitis, properly so called, which 

 he names Jacchus, and whose peculiar characters are pointed in- 

 ferior incisors, arranged on a curved line, equal to the canines. Their 

 tail is annulated and well covered with hairs; the ears generally or- 

 namented with a tuft. 



Sim. jacchics, Lin.; in Paraguay the Titi. (The Common 

 Ouistiti.) Tail tolerably well tufted, coloured in rings of 

 brown and white ; body greyish-brown ; two large tufts of white 

 hairs before the ears. From nearly every part of South Ameri- 

 ca.(2) 



N.B. This name of Gigo or Guigo is given by Pr. Mas. to his MdanocJdr, so that 

 we must consider it generic. 



(1) Add Ifydipithec. felinus, Spix, pi. 18. 



(2) It is difficult to establish very specific limits between Ouistitis of different 

 colours. The Jucch. penicillatus, Geoff., Spix, pi. 26, has a white spot on the 

 forehead, and the tufts of the ears bi-own or black. His /. leucocephalus, Pr. Max., 

 lib. 2, has the same tufts, but the whole head and fore part of the neck are 

 white. His /. humeralifer has the breast, shoulders and arms white. The /. al- 

 bicollis, Spix, pi. 25, has the spot on the forehead, tufts of the ears and a large 



