FOSSIL MAMMALIA. 



15 



sphere of observation was limited to a comparatively small part of South Ame- 

 rica ; and the future traveller may fairly hope for similar success, if he bring to 

 the search the same zeal and tact which distinguish the gentleman to whom 

 Oryctological Science is indebted for such novel and valuable accessions. 



It is remarkable that all the fossils, collected by Mr. Darwin, belong to her- 

 bivorous species of mammalia, generally of large size. The greater part are refer- 

 rible to the order which Cuvier has called Edentata, and belong to that subdivi- 

 sion of the order (Dasypodidce) which is characterized by having perfect and some- 

 times complex molar teeth, and an external osseous and tesselated coat of mail. 

 The Megatherium is the giant of this tribe; which, at the present day, is exclu- 

 sively represented by South American species, the largest (Dasypus Gigas, Cuv.) 

 not exceeding the size of a Hog. The hiatus between this living species and the 

 Megatherium, is filled up by a series of Armadillo-like animals, indicated more 

 or less satisfactorily by Mr. Darwin's fossils, some of which species were as large 

 as an Ox, others about the size of the American Tapir. The rest of the collection 

 belongs, with the exception of some small Rodents, to the extensive and hetero- 

 geneous order Pachydermata ; it includes the remains of a Mastodon, of a Horse, 

 and of two large and singular aberrant forms, one of which connects the Pachy- 

 dermatous with the Ruminant Order ; the other, with which the descriptions in 

 the following pages commence, manifests a close affinity to the Rodent Order. 



