LIFE OF TERTIAKY PEFaOD 251 



the pampas of various ages. Their great richness and im- 

 portance may be indicated by the following enumeration of 

 the chief orders of Mammalia represented in them. 



Of the Peimates (or monkeys) all the remains are of the 

 peculiar American families Cebidas and Ilapalida:', with one 

 extinct genus of the fonner. Bats (the order Chiroptera) are 

 abundant, with several peculiar genera. The Insectivora arc 

 very rare in South America, but a fossil has been found sup- 

 posed to belong to the peculiar West Indian family Solenodon- 

 tidge. The Carnivora are chiefly represented by fossils of the 

 American family Procyonidse (comprising the racoons and 

 coati-mundis), of which several extinct genera have been ol>- 

 tained. The hoofed animals (Ungulata), which, from tlieir 

 great abundance in a living state in every part of the world, 

 and their habit of living together in great herds often of many 

 thousands, have been most frequently preserved in a fossil 

 state, are here represented not only by all the chief forms that 

 still inhabit the country, but also by some which are now 

 only found in other continents, as well as by many which arc 

 altogether extinct. Among the former the most interesting 

 are true horses of the genus Equus, as well as two peculiar 

 genera of ancestral Equidge, distinct from those so abundant 

 in I^orth America. There are also several ancestral forms 

 of the Llama tribe, one of which, Macraiichenia patacJionica, 

 was as large as a camel; and there are others so distinct as to 

 form a separate family Proterotheriidse. 



Another sub-order, Astrapotheria, were more massive ani- 

 mals, some of which equalled the rhinoceros in size. They 

 consist of two distinct genera, only found in the Patagouian 

 deposits of Mid-Tertiary age.-^ 



Still more remarkable is another group — the Toxodontia — 

 sometimes exceeding the rhinoceros in bulk, but with teeth 

 which approached those of the Rodentia; of these there are 

 various forms, which are grouped in three distinct families. 

 The skeleton of one of the most remarkable of this group is 



iLydekker's Geographical History of Mammals, p. 81. 



