10 
crown with short hair; the chin scarcely bearded ; the lower cutting 
teeth very much shelving ; legs elongate. 
This genus forms part of the genus Brachywrus of Spix; and if 
Spix had not evidently described the teeth, &c. of his first species in 
his generic character, I should have been induced to have retained for 
this group the name of Brachyurus, which is more applicable to it 
than to the one to which it is applied; and indeed M. Isidore Geof- 
froy appears to have so applied it. 
Several species have been described which chiefly differ in the length 
of the tail; as, 1. Ouakaria Spixii; Brachyurus Ouakari, Spix, 
Brazil, t. 8, with the tail about one-third the length of the body. 
2. Ouakaria calvus; Brachyurus calvus, I. Geoff. Rev. Cuvier. 1847, 
137, much paler in colour, but it is very doubtful if the shortness of 
the tail does not depend on the imperfection of the specimen, and the 
colour on partial albinism. 
We have specimens of B. calvus in the British Museum, presented. 
by M. Bourcier. The skull may be thus described :— 
The cutting teeth projecting ; 
the upper one broad, especially 
the two middle ones; lower one 
elongate, narrow, more sloping, 
and projecting like those of Indrt. 
Canines conical, far away from 
the cutting teeth, leaving a large 
vacancy ; flattened in front ; they 
are flattened before and behind, 
placed rather obliquely, with a 
sharp inner edge. The skull is 
very unlike that of the Cebide ; 
most allied to that of Pithecia 
leucocephala,but the cutting teeth 
in that species are not so proclined. 
The converging, slender, shelving, cutting teeth in the lower jaw 
of this genus, as well as its slender limbs and the shortness of its tail, 
bear a certain resemblance to the Indri amongst the Lemuride. 
The form of the lower jaw also offers a good character for the 
distinction of the genera. 
1. Lower jaw not dilated behind. 2. Lower jaw dilated behind. 
eral tars 
Atelina (part). Mycetina. 
Ateles. Mycetes (much). 
Cebina. Lagothrix (moderately). 
Cebus. Atelina (part). 
Pitheciana (part). Brachyteles (moderately). 
Pithecia. Callitrichina. 
Jacchina. Callithrix. 
Jacchus. Chrysothrix. 
Midas. Nyctipithecus. 
Pitheciana (part). 
Brachyurus. Ouakaria. 
