230 Zoological Society. 
Lower jaw not produced on the upper edge between the teeth, but 
slightly keeled in front of the chin. : 
Face with a black streak from the back angle of the eye. 
Cuvier, Oss. Foss. v. t. 4, figured the skeleton, and t. 5, the skull 
and bones of the feet of this genus; the skull is copied R. A. Illust. 
t. 70.f. 1a. Wiedemann, Arch. Zool. und Zoot. i. t. 1 and 1*, and 
Spix, Cephal. t. 7. f. 12, figure the skull, and Blainville figured two 
skulls belonging to this genus in his ‘ Osteographia.’ 
In the young skull there is sometimes a slight projection on the 
front edge of the zygomatic arch, assisting to form the back edge of 
the orbit, but this process seems soon to disappear as the animal 
increases in size, and I have not found it in any of the older skulls. 
Cuvier, Desmarest, and most French authors, have considered all 
the individuals of this genus as belonging to one species, and have 
given an indefinite description, so as to include them. Cuvier (Rég. 
Anim. ed. 1. 217) thus describes that species: ‘‘ Sa couleur est grise, 
souvent tachetée sur le dos de brun et de blanc: plusieurs individus 
portent entre les épaules une tache d’un fauve vif que traverse une ligne 
longitudinale.” He refers for the species to both Buffon’s figures, 
xii. t. 5 & 6. In the second edition he remarks, ‘On connait un 
Ai dit la dos briilé, parce qwil a entre les épaules une tache noire en- 
tourée de fauve ; ce n’est selon M. Temminck, qu’une variété résultant 
de c2 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. erinitus (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 d. 
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. 
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. iu. t. 11. 
Ai a dos brilé, Buffon, Hist. Nat. xiii. 62. 
Ai adult, Buffon, Hist. Nat. xiii. 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. Ilust. Mamm. t. 70. 
au 
