LIFE OF TERTIARY PERIOD 259 



dor. But in 1895 a larger species of the same genus was 

 obtained from Bogota; and it was then seen that they be- 

 longed to a group of which large numbers of fossil remains 

 had been found in the Santa Cruz beds. By a comparison 

 of these remains of various allied forms with the specimens 

 of those now living, it seems no longer possible to doubt that 

 marsupials of Australian type have existed in South America 

 in Middle or Late Tertiary times, and tiiat some of them 

 survive to-day in the equatorial Andes, where their small size 

 has probably saved them from extinction. Of these latter, 

 Mr. Lydekker says: "In the skeleton the lower jaw exhibits 

 the usual inflexion of the angle ; and the pelvis carries 

 marsupial bones. A small pouch is present in the female." 

 These small marsupials have been named Csenolestes, while 

 their fossil allies are so numerous and varied that they have 

 to be classed in three families — Abderitidae, Epanorthidse, 

 and Garzoniidae. This is only mentioned here to show the 

 large quantity of materials upon which these conclusions are 

 founded. 



Teachings of Pleistocene Mammalia 



For the purpose of the present work it is not necessary to 

 go into further details as to the development of the higher 

 forms of life, except to call attention to some other cases of 

 the sudden dying out of great numbers of the more developed 

 species or groups during the most recent geological period — 

 the Pleistocene. 



It has already been shown how, in temperate South 

 America, the huge sloths and armadillos, the giant llamas, 

 the strange Toxodontia, and the early forms of horses all 

 disappeared at a comparatively recent epoch. In Xorth 

 America a similar phenomenon occurred. Two extinct lions; 

 a number of racoons and allied forms, including several ex- 

 tinct genera; six extinct species of horses; two tapirs; two 

 genera of peccaries ; a llama and a camel ; several extinct 

 bisons, sheep, and deer; two elephants and two mastodons, 



