NO. 9 MAMMALS FROM CAVES IN HAITI MILLER 25 



of the shaft in its narrowest region are 12.2 and 8.2, while in one 

 specimen from Porto Rico they are 10.8 and 8.8, and in another 13.0 

 and 9.8. 



Specimens cxauiiued. — ]\Iandil)]e and piece of an incisor from the 

 crooked cave near the Atalaye plantation ; hroken femur from the 

 small cave of the same group. 



XENARTHRA 



The occurrence of ground sloths in Hispaniola was not known he- 

 fore the discovery of a few hones in the St. Michel caves hy Mr. Brown 

 and Mr. Burhank. On the basis of this scanty material — four vertebrae, 

 three of them imi:)erfect, a piece of a limb bone of a young animal, 

 and a fragment of a rib — I was unable to refer the species to 

 any genus, and. at Doctor Matthew's suggestion, 1 recorded it ' as 

 Megalocnus ? sp. ? 



On visiting the caves myself I secured teeth and a femur resembling 

 the corresponding parts of the Porto Rican Acratociius and also a 

 calcaneum so unlike that of Acratociius as to suggest the existence 

 of two sloths differing generically from each other. The material 

 collected by Mr. Poole now makes the definite separation of these 

 animals possible. One is slender limbed, resembling Acratociius in 

 size and general features ; the other is more heavy, its general build 

 probably somewhat as in NotJirotJierium sJiastense. Its bulk, however, 

 though considerably exceeding that of Acratocnus, is not likely to have 

 been much more than one-fourth that of the Californian animal. 



That one or both of these sloths continued to exist on the island 

 until after the advent of man I have no doul)t. The facts which have 

 led me to this conclusion are as follows: (a) In the two caves near 

 St. Michel most of the sloth remains were found within two feet of 

 the surface ; and human l)ones and pottery occurred to the same depth 

 without any indication that they had been dug in. (b) Near the en- 

 trance to the smaller of the two main caves bones of ground sloths 

 (certainly two and perhaps more individuals) were inextricably mixed 

 with bones of man (adult and infant) and domestic pig. The remains 

 were scattered among the small fragments of limestone which made 

 up the greater part of the floor material, and I was unable to deter- 

 mine any definite level-relationship among them, (c) Near the en- 

 trance to the large cave I unearthed with a trowel, in fine, soft, undis- 

 turbed material at the bottom of a trench two feet deeji, the femur 



' Smithsonian Misc. Coll., Vol. 74, No. 3, p. 6, October 16, 1922. 



