56 MAMMALIA. 



The Common Sapajous have the head Hat, 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 Chameh, Ateles pentadactylus, Geoff,, 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, Jt. hypoxanthus, Pr. Max. ; 

 Brachyteles macrotarsus, Spix, pi. 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 Brachyteles. They connect the Ateles 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; Simla panisc. L. ; Coaita, Buff. XV. 1. (The 

 Coaita). Completely covered with black hair, like the Cliamek, 

 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, Geoff. The Chwva, Humb. or the Coaita a face 

 bordee, Ann. Mus. XII. pi. 10. Black, with a border of white 

 hairs round the face. 



A. belzehuth; Sim. beelzeb., Briss. The Marimonda, Humb. or 

 Coaita a ventre blane, Geoff.; Ann. Mus. VII. pi. 16. Black 

 above; white beneath; circumference of the eyes flesh-coloured. 



A. arachnoides, Geoff. Ann. ISIus. XIII. pi. V. (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 slowf. 



barhatus, Spix, pi. 32. The female, ib. pi. 33, is of a light yellowish grey. The 

 male must be the Mycetes 7iiger of Kuhl and Prince IVIaximil. de Neuwied. The 

 Caraia of d'Azzara, which is black, breast and belly of a dark red, the female 

 brownish, may be refeiTed to this species. 



Pr. Max. has another Mycetes ursinus, which appears to be much browner than 

 the ursinus of M. Geoflroy, and to approximate nearer to the M.fuscus, or the M. 

 discolor of Spix, pi. 30 and 34. This latter rather appears to be the St.fuscus of 

 GeofFroy. 



The Straw-coloured Alouatte, Stentor stravmieus, Geoff, and the Myc. stramineus, 

 Spix, pi. 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 St. flavicaudatus, Geoff, of a black brown, with a yellow streak on each 

 side of the tail. 



* Ann. du Museum, VII. 260, et seq. 



f They exhibit some remarkable resemblances to man in tlieir muscles. Of all 

 animals, they alone have the biceps of the thigh made like ours. 



