58 MAMMALIA. 



Ill the Saimiri the tail is depressed, and almost ceases to be prehen- 

 sile; the head is very much flattened; in the intcrorbitar partition of the 

 skeleton there is a membranous space. There is only one known ; the 

 (S/mm scmrea, Buff. XV. 10. (The Saimiri). Size of a squirrel ; 

 of a yellowish grey ; fore-arms, legs, and the four extremities of a 

 yellowish fawn-colour ; end of the nose quite black. 

 Those of the American monkeys, whose tails are not at all prehensile, 

 are called Sakis*. Several of them have the tail long and tufted, whence 

 they have been also termed Fox-tailed Monkeys : their teeth project for- 

 wards more than those of the others. They are the Pithecia of Des- 

 marets and lUiger. 



Simia pithecia, L. ; Buff. XV. 12; Pithecia inusta, Spix, pi. 10. 

 (The Yarke). Blackish ; circumference of the face whitish. 



Pith. Jiirsuta, Spix, pi. 8. (The Grey Sakis). Grey ; with yel- 

 lowish hands. 



S'imia safanaSjUohnansegg; Humb. Obs. Zool. L. xxvii. (The 

 Black Saki). All black. 



Pith, rtifiventris, Geoff.; Buff. Supp. VII. 31; Pith, capilla- 



mentosa, Spix, pi. 11. (The Red-bellied Saki). Brown, with a 



red belly. 



Spix distinguishes those species whose tails, although tufted, are shorter 



than the body, by the name of Brachiurus. His Br. Ouarahi, Sp. 



pi. 8, has a fawn-coloured body; head, neck, arms, and feet black. To 



this should be referred, provided always it is another species, the Sim. 



melanocephala, Humb. Obs. Zool. p. 29 ; yellow, with a black head. 



In some, also, the Callithrix, Geoff, or Sagouins, Fr. Cuv. the tail 

 is slender, and the teeth do not project. The Saimiri were associated 

 with them for a long time, but the head of the Sagouins is higher, and 

 their canine teeth much shorter. Such are the 



Call, personata, Geoff., Spix, pi. 12; Call.nigrifrons, id. 15. (The 

 Masked Monkey). A yellowish grey ; head and hands black. 



Call. liKjens; S. /«</e»s, Humb. (The Mourning or Widow Mon- 

 key). Blackish, with a large white gorget or neck-piece. The 

 Call, amicta, Geoff., Sp. pi. 13, and the Call, torquata, Hofraansegg, 

 can differ but little from this species f. 



NocTHORUs, Fred. Cuv. — Nyctipithecus, Spix. Improperly called 

 Aotus by lUiger. 

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



* All the American monkeys, whose tails are not prehensile, together with tlie 

 Ouistitis, are termed by Buffon Sagouins (Callithrix, Erxl.) This name of 

 sagouin or cagui is in fact applied in Brazil to all tlie little Quadrumana, whose tails 

 are not prehensile. 



N.B.— M. Geoff., Ann. Mus. XIX. 112, 113, gives to his Callithrix, which are 

 merely a division of those of Erxleben — Nocthortts and Pithecia, the common name 

 of Geopiihecus. 



t Add Call.mclanochir, Pr. Max. — C.cinerasccns, Spix, pi. 14, is the young of the 

 same according to Temminck. — C. ciiprea, Spix, pi. 17. — C. gigo, id. pi. Ifi. N B. — 

 This name of Gign or Gtiigo is given by Pr. Max. to his Melanochir, so that we must 

 consider it generic. 



