112 F. E. Clements 



surface and cover (Kowalevsky, 1873; Osborn, 1910:238). The 

 proboscideans are less satisfactory indicators, and the rodents 

 are significant chiefly in connection with the food coactions and 

 soil reactions that the same species or genera exhibit in the mod- 

 ern biome. 



PLEISTOCENE 



The selection of the following formations during the three 

 periods of the Pleistocene, Pliocene, and Miocene has been de- 

 termined in large measure by position in the desert region, or 

 proximity to it, or location in a climate similarly the result of 

 mountain-making processes. The number of genera represented 

 has also been a consideration of importance, though not suffi- 

 cient to warrant including the rich faunas of the Potter Creek 

 and Samwel Caves of northern California, which belong in a 

 cUmate of much higher rainfall. For the reasons already given, 

 the water birds are omitted except for the McKittrick area, where 

 they are included for the purpose of suggesting the animal 

 members of the water community in the Pleistocene (see Grin- 

 nell, 1923:54-60). 



Lake Manix 



MAMMALS 



Ungulates — 



Equus, large Camel, small 



Equus, small Antilocapra 



Camelops ? large 



Proboscideans — 

 Elephas or Mastodon 



Bautista Creek 



MAMMALS 



Ungulates — 



Equus Antilocapra 



Tapirus Odocoileus 



Camelid Capromeryx 



