2. BKADtPtrs. 363 



1. CHOLfflPXJS. 



Hands two-clawed ; feet tiree-elawed. l*roiit grinder large, like 

 a canine. Pterygoid bone rather swoUen, vesicular. 



Osteology.— Guyiev, Oss. Foss. v, j). 73, t. ^, 7 ; Gray, P. Z. S. 1849, 

 p. 65 ; Turner, P. Z. S. 1851, p. 207; BlaiuYiUe, Osteogr. t. 



Choloepus, lUiger, 1811 ; Gray, P. Z. 8. 1849, p. 65 ; JRapp, Edent. 

 Bradypus, F, Ciw. Dents Mam. t. 77. 



1. Choloepus didactylns. (XJnau.) B.M. 

 " Cervical vertebrae 7; arms and claws long." 



Bradypus didactylus, Imn. 



Bradypus linau et Bradypus curi, lank. 



Cholcepus didactylus, Gray, Cat. Mamm. B, M. ji. 192 ; Proe. Zool. 



Soc. 1849, p. 65 ; Turner, P. Z. 8. 1851, p. 206 ; Ovbm, Odont. t. 81. 



f. 3, 4 (fcom Blairw.) ; Bapp, Edent. p. 4, t. 3. f. 2 (skull). 



Hah. Brazil aud Guiana. 



2. Choloepns HofEiuaniii. B.M. 



" Cervical vertebrae 6 ; arms shorter ; claws short." 



Cholcepus Hofimanm, Peters, Monatsh. Akad. Berl. 1868, p. 128 ; 

 Nat. Hist. Ben. 1865, p. 300. 



Ba6. ^orto Eico^ Gc^S^^S-^-^-*^."*^ 



Dr. Peters has des6ribed the Sloth from Porto Eico as a species 

 under the name of Ghdloe.pus Eoffmanni (Monatsb. Berl. Akad. 1858, 

 p. 128), because it has six cervical vertebrae ; but the number of 

 the free vertebrae ia the genus appears froifii his own observations 

 to be variable. 



" Dr. Peters had received five skeletons of this Sloth, in all of 

 which the number of cervical vertebrae was six. In four of the spe- 

 cimens these vertebrae were all separate ; in the fifth specimen the 

 second and third had become united, as is sometimes the case in 0. 

 cUdaetylus ; and in this example, moreover, the sixth cervical had 

 coalesced with the first dorsal vertebra." — Nat. Hist. Rev. 1865, 

 p. 300. 



2. BRADYPUS. 



Hands and feet three-clawed. Front grinder small. Pterygoid 

 swollen, hollow, vesicular (P. Z. S. 1849, t. 10). Skull flattened 

 stbove on the forehead. 



OsUology. — Cuvier, Oss. Foss. v. p. 73, t. 4, 5, 7 ; Gray, P. Z. S. 

 1849 ; Turner, P. Z. S. 1851, p. 207. 



Bradypus, lUiger, 1811 ; Gray, I. c. 1849, p. 66; Bapp, Edent. p. 5. 

 ? Acheus, F. Cuv. Dents Mam. t. 78. 

 Arctopithecus, Gesner. 



" The female brought forth a young one whilst in my custody ; 

 she did not carry it on her back, but in her lap. Nevertheless, 

 when the young one is older, it appears to me that the most con- 



