70 
tourée de fauve ; ce n’est selon M. Temminck, qu’une vari¢té résultant 
de ce que des longs poils de ses épaules sont usés.”—Cuvier, Reg. 
Anim. ed. 2. p. 225. 
Desmarest describes it in nearly the same words, but he notices 
four varieties, including amongst them B. crinitus (var. c.) ; the spe- 
cial description of the species and var. 6. appear to be 4. gularis; 
var. a. appears to be from a female, and var. d. from a male of A. 
flaccidus. 
Knorr (Délices, i. 97. t. K. f. 3) figures the foetus of a species of 
this genus. 
a. Fur moderately rigid ; the back white-spotted ; dorsal streak 
elongate. 
1. ARCTOPITHECUS GULARIS. 
(Lower jaw, Mammalia, P|. XI. f. 6.) 
Dark grey-brown; back white varied, with an elongated black 
streak, with a broad patch of soft yellow hair on each side between 
the shoulders. Skull with a broad forehead, rather convex over the 
back part of the orbits. The upper front grinder rather large. The 
hinder side of the lower jaw concavely cut out, and with the lower 
angle slender and acutely produced ; front of the lower jaw flat, not 
keeled up the suture. 
Bradypus gularis, Riippell, Mus. Senckenb. iii. t. 11. 
Ai a dos brilé, Buffon, Hist. Nat. xiii. 62. 
Ai adult, Buffon, Hist. Nat. xii. t. 6. 
B. tridactylus, Griffith, A. K. iv. 271. 
B. tridactylus, description and var. 6. Desm. Mamm. 
D’ Ai B. tridactylus, var. Cuvier, Rég. Anim. Illust. Mamm. t. 70. 
tp 
A. tridactylus, var. Cuvier, Oss. Foss. v. t. 5. f.1, 2, 3, skull; cop. 
Cuv. R. A. Ed. Illust. t. 70. f. 1 a. 
B. tridactylus 6, Fischer, Syn. 387. 
Hab. Bolivia, Bridges; Guiana, Riippell. 
This species was well-described by Buffon, and is at once known by 
its dark colour, white varied back, and the yellow patch of soft hair 
between the shoulders. 
Cuvier states (Rég. Anim. ed. 2) that M. Temminck thought that 
the yellow spot on the back depended on the skin being worn in that 
part. Probably he never saw a specimen, or he could hardly have 
made such an observation. 
According to Mr. Waterhouse, Mr. Bridges considers the specimens 
here described as the males of 4. marmoratus. 
Cuvier’s upper figure of the skull (fig. 1) most accurately represents 
the form of the hinder end of the lower jaw, the other figures being 
distorted by the perspective position. 
The skull from which the end of the lower jaw is figured was from 
an adult animal. There is also the skeleton of a young specimen 
from the same locality in the Museum collection, which only differs 
in the coronoid process being less developed. There are two speci- 
