58 MAMMALIA. 
In the Sarmrrt the tail is depressed, and almost ceases to be prehen- 
sile; the head is very much flattened; in the interorbitar partition of the 
skeleton there is a membranous space. ‘There is only one known; the 
Simia sciurea, 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 Saxis*. 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 Pirnecta of Des- 
marets and Illiger. 
Simia pithecia, L.; Buff. XV. 12; Pithecia inusta, Spix, pl. 10. 
(The Yarke). Blackish; circumference of the face whitish. 
Pith. hirsuta, Spix, pl. 8. (The Grey Sakis). Grey; with yel- 
lowish hands. 
Simia satanas, Hofmansegg; Humb. Obs. Zool. L. xxvii. (The 
Black Saki). All black. 
Pith. rufiventris, Geoff.; Buff. Supp. VII. 31; Pith. capilla- 
mentosa, Spix, pl. 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 Bracururus. His Br. Ouaraki, Sp. 
pl. 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 CatiiTurix, 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, pl. 12; Call. nigrifrons, id. 15. (The 
Masked Monkey). A yellowish grey; head and hands black. 
Call. lugens; S. lugens, Humb. (The Mourning or Widow Mon- 
key). Blackish, with a large white gorget or neck-piece. The 
Call. amicta, Geoff., Sp. pl. 13, and the Call. torquata, Hofmansegg, 
can differ but little from this species}. 
Noctuorus, Fred. Cuv.—NyctieituHecus, Spix. Improperly called 
Aotus by Mliger. 
Only differs from the Sagouins in its great nocturnal eyes, and in the 
* All the American monkeys, whose tails are not prehensile, together with the 
Ouistitis, are termed by Buffon Sacovuins (CaniiTurix, Erxl.) This name of 
sagouin or cagui is in fact applied in Brazil to all the little Quadrumana, whose tails 
are not prehensile. 
N.B.—M. Geoff., Ann. Mus. XIX. 112, 113, gives to his Callithriz, which are 
merely a division of those of Erxleben—Nocthorus and Pithecia, the common name 
of Geopithecus. 
} Add Call. melanochir, Pr. Max.—C. cinerascens, Spix, pl. 14, is the young of the 
same according to Temminck.—C. cuprea, Spix, pl. 17.—C. gigo, id. pl. 16. N B.— 
This name of Gigo or Guigo is given by Pr. Max. to his Melanochir, so that we must 
consider it generic. 
