chap, vii.] MAMMALIA OF THE NEW WORLD. 145 



extinct species. Cercolabes, the ' tree porcupine ' (Cercolabidae) 

 has two species, one as large as a peccary ; Myopotamus, Loncheres, 

 Carterodon, are existing genera of spiny rats (Echimyidre) ; 

 and there are two extinct genera of the same family, Lonclw- 

 phorus and Phyllomys. Lagostomus (Chinchillidre), the visca- 

 cha of the Pampas, is represented by an extinct species. 

 There is also an extinct species of Lcpus ; several species of 

 Hesperomys and Oxymycterus ; and a large Arvicola, a genus not 

 living in South America. 



Edentata. — These, which constitute the great feature of the 

 existing South American fauna, were still more abundant and 

 varied in the Cave period, and it is remarkable that most of 

 them are extinct genera. The armadillos are alone represented 

 by living forms, Dasypus, and Xenurus ; Eiirydon and Hetero- 

 don, are extinct genera of the same family, as well as Chlamydo- 

 therium — huge armadillos the size of a tapir or rhinoceros, and 

 Pachytherium, which was nearly as large. The ant-eaters are 

 represented only by Glossotherium, an extinct form allied to 

 Myrmecophaga and Manis. The sloths were more numerous, 

 being represented by the extinct genera Ccelodon, Sphenodon 

 and Ochotherium, the last of large size. The huge terrestrial 

 sloths — Megatheridae, also abounded ; there being species of 

 Megatherium and Megalonyx, as well as the allied Scclidotherium, 

 supposed to have some affinity for the African Orycteropus. 



Marsupials. — No new forms of these appear, but numerous 

 species of Didelphys, all closely allied to opossums still living 

 in South America. 



The preceding sketch of the wonderful cave fauna of Central 

 Brazil, is sufficient to show that it represents, in the main, a 

 period of great anticpiiity. Not only are almost the whole of 

 the species extinct, but there are twenty extinct genera, and three 

 others not now inhabitants of South America. The fact that so 

 few remains of the living animals of the country are found in 

 these caves, indicates that some change of physical conditions 

 has occurred since they were the receptacles of so many of the 

 larger animals; and the presence of many extinct genera of 



