56 MAMMALIA., 
The Common Sapasous have the head flat, and the muzzle slightly 
prominent—facial angle 60°. 
In some of them, the anterior thumbs are either totally, or nearly so, 
hidden under the skin, and the prehensile part of the tail naked beneath. 
M. Geoff. has formed them into a genus by the name of ATELES*. 
The first species, the Chamek, Ateles pentadactylus, Geoft., differs 
again from the others in having a slight projection of the thumb, 
though it is only of one phalanx, but without a nail; its fur is 
black. 
A second species, the Mikiri, At. hypoxanthus, Pr. Max.; 
Brachyteles macrotarsus, Spix, pl. i., has also a very small thumb, 
and sometimes even a nail. The fur is yellowish, ferruginous to- 
wards the tail. These two species are separated by Spix under the 
name Bracuytetes. They connect the Atéles with Lagothrix. 
The other ATELEs to which alone Spix restricts that name—Coaita, 
Buff.—have no apparent thumb whatever. Such are the following: 
A. paniscus; Simia panisc. L.; Coaiia, Buff. XV.1. (The 
Coaita). Completely covered with black hair, like the Chamek, 
but without any visible thumb; face, flesh-colour. 
A. ater, Fr. Cuv. Mammif. (The Cayou). Face black, like the 
rest of the body. 
A. marginatus, Geott. The Chuva, Humb. or the Coaita a face 
bordée, Ann. Mus. XII. pl. 10. Black, with a border of white 
hairs round the face. 
A. belzebuth; Sim. beelzeb., Briss. The Marimonda, Humb. or 
Coaita a@ ventre blanc, Geoff.; Ann. Mus. VII. pl. 16. Black 
above; white beneath; circumference of the eyes flesh-coloured. 
A. arachnoides, Geoff. Ann. Mus. XIII. pl. 9. (The Spider 
Monkey). Grey, fawn-coloured or red; eyebrows black. 
All these animals are natives of Guiana or Brazil; their fore-feet 
are very long and slender, and their gait remarkably slow f. 
barbatus, Spix, pl. 32. The female, ib. pl. 38, is of a light yellowish grey. The 
male must be the Mycetes niger of Kuhl and Prince Maximil. de Neuwied. The 
Caraia of @Azzara, which is black, breast and belly of a dark red, the female 
brownish, may be referred to this species. 
Pr. Max. has another Mycetes ursinus, which appears to be much browner than 
the ursinus of M. Geofiroy, and to approximate nearer to the M. fuscus, or the M. 
discolor of Spix, pl. 830 and 84. This latter rather appears to be the St. fuscus of 
Geoffroy. 
The Straw-coloured Alouatte, Stentor stramineus, Geoff. and the Myc. stramineus, 
Spix, pl. 31, of a yellowish grey, appears from its cranium to be of a different spe- 
cies, but it may merely be the female of a preceding one. It is easily seen, also, that 
if their characters are so uncertain, their synonymes must be much more so. 
Add the S¢. flavicaudatus, Geoff. of a black brown, with a yellow streak on each 
side of the tail. 
* Ann. du Museum, VII. 260, ect seq. 
+ They exhibit some remarkable resemblances to man in their muscles, Of all 
-animals, they alone have the biceps of the thigh made like ours. 
