CHAP. III.] 



VERTEBRA AND RIBS : BRADYPUS. 



119 



possible. Welcker's list does not, I believe, include any of the 

 specimens separately given in No. 44. 



The determination of the species is quite uncertain. Welcker 

 in his analysis does not divide the species of Bradypus. In the 

 other cases I have simply taken the name given on the labels. As 

 regards Choloepus the confusion of species is much to be regretted, 

 for according to the received account 1 the more northern species, 

 C. hoff'manni, has only 6 cervicals, while C. didactyliis has 7. In 

 the table it will be seen that four specimens in different places 

 have C 6, though generally marked C. didaotylus. Possibly 

 some or all of these are C. hoffmanni, and I have therefore entered 

 them as Choloepus sp. In the case of Bradypus it has not been 

 alleged that the number of cervicals characterizes particular 

 species, so the fact that the species are confused is of less con- 

 sequence. 



*44. Bradypus. 



1 FLOWER, W. H., Mammals, Living and Extinct, 1891, p. 183. 



2 GRUBER, Mem. Imp. Ac. Sci. Pet. Ser. vn., xin. 1869, no. 2, p. 31. 



3 STRUTHERS, Jour. Anat. PJnj*., 1875, p. 48 note. 



4 DE BLAINVILLE, Osteogr., Fsc. v., pp. 27, 28 and 64. In the place cited, 

 de Blainville gives C 9, D 16, L 3, S 6, C 911 as the normal, but he does not say 

 in how many specimens this formula was seen. I have therefore been unable to 

 tabulate this observation. It will be seen that D 16 is quite exceptional, but as it 

 occurred in the Coll. Surg. specimen no. 3422 it was -described by OWEN as the 

 normal, and this statement has been copied by many authors, perhaps by de Blainville. 



5 Fourth lumbar ankylosed to sacrum by tr. proc. 



