540 THE AGE OF MAMMALS 



f Perimys. INIioc, S. Amer. 



f Megamya. Giant Cliinchilla. Plioc, Argentina. 



^ Amhlyrhiza. Giant Cliincliilla. Pleist., W. Indies. 



Chinchilla. Cliinchilla. Ande.s Mts. 



Lagostomus. Viscacha. Argentine (since Plioc). 



Lnr/idium. Four-toed Chinchilla. Andes Mts. 

 Fam. Dinomyidae. Long-tailed Pacas. 



Dinomys. Branick's Paca. Peru. 

 Fam. Dasyproctidae. Agoutis. 



Coelogenys. Paca. Paraguay to C. Amer. (Pleist., S. Amer.). 



Dasyprocta. Agouti. Paraguay to Mexi. (Pleist., S. Amer.). 

 Fam. Caviidae. Cavies. 



■f- Eocardia. U. IMioc, S. Amer. 



f Schistomys. U. Mioc, S. Amer. 



Cavia. Guinea Pig. S. Amer. (since Plioc). 



Hydrochcents. Capybara. Guiana to Uruguay (since Plioc). 



Dnlichotis. Patagonian Cavy. Argentine (since Plioc). 

 Inc. Sed. 



f Cephalomys. Eoc, S. Amer. 

 I?ic. Sed. Edentata. 



VIII. Order TiENIODONTA. Ta?niodonts (Ganodonts), primitive Eden- 



tates with enameled teeth. ^ 



Fam. Conoryctidae. Conoryctids. 



t Onychodectes. Bas. Eoc, N. Amer. 



t Conorycteii. Bas. Eoc, N. Amer. 

 Fam. Stylinodontidae. Stylinodonts. 



t ' Hemiganus' (= Wori mania). Bas. Eoc, X. Amer. 



f Psittacotherium. Bas. Eoc, N. Amer. 



f Calamodon. L. Eoc, N. Amer. 



f Sljilinodon. L. to M. Eoc, N. Amer. 



IX. Order ' EDENTATA' (Xenarthra). American Edentates.'^ 

 1. Suborder 'PlLOSA' (= Anicanodonta). Hairy Edentates. 



1 Vide Wortman, .J.L. The Ganodonta and their Relationship to the Edentata. Bull. Amer. 

 Mus. Nat. Hist., Vol. IX, 1897, pp. 59-110. The supposed ancestral relationship of the Gano- 

 donta (Ta^niodonta) to the Edentates is denied hy Seott (]Mammalia of the Santa Cruz Beds, 

 Edentata. Princeton UniverKity, Exped. to Patagonia, Vol, V, 1903-liK)5). 



2 Vide Flower and Lydekker, Introduction to the Study of Mammals, 1892; Weber, Die Siiu- 

 getiere, 1900 ; Scott, Mammalia of the "Santa Cruz Beds, Edentata. Princeton Patagonian 

 Exped., Vol. V. The present arrangement is by Osborn and Matthew. 



