444 W. F. BLAIR 



significant distribution is that of an extinct bog lemming {Synap- 

 tomys australis), which is known from the Pleistocene of Florida 

 (Sherman, 1952) and from the Jinglebob fauna (Sangamon) of 

 southwestern Kansas (Hibbard, 1955b). 



Ground sloths, which presumably depended on trees for browsing, 

 have been recorded from various localities in the present grasslands. 

 Paramylodon is known from the Jinglebob (Sangamon) fauna of 

 southwestern Kansas, where its fossils are associated with pine 

 (Pinus) and Osage orange (Madura) pollens (Hibbard, 1955b). This 

 sloth is also known from various localities in Colorado, Nebraska, 

 and Texas in the area of the present grasslands, and Nothrotheriiim 

 is known from such presently arid grasslands as the Big Bend region 

 and panhandle of Texas (Hay, 1924). 



Tapirs {Tapir us) are even more indicative of forests than ground 

 sloths. These have been recorded from the present grasslands in 

 north central Oklahoma and as far west as El Paso, Texas (Hay, 

 1924) and southwestern Oklahoma (Hibbard, 1957). A mandible in 

 the Centennial Museum, Texas Western College, from a cave in the 

 Hueco Mountains, Texas, is not permineralized and possibly repre- 

 sents a late occurrence of the tapir in this presently arid and treeless 

 region (W. S. Strain, oral communication). 



The preceding evidence implies that vastly different conditions pre- 

 vailed at times during the Pleistocene, where grasslands exist today. 

 It seems reasonable to hypothesize that under the vast shifts of 

 climatic regimes that characterized the Pleistocene a wide spectrum 

 of conditions from moist to arid might be expected to have existed 

 in the present grasslands in various combinations with temperature 

 conditions. 



Relations of the Floridian Vertebrates 



The present Floridian fauna includes various animals that have 

 been there for a long time, including some that have their nearest 

 living relatives in eastern Asia, but this circumstance is not perti- 

 nent to the present discussion except as it indicates the long-con- 

 tinued existence in the Southeast of a faunal center of distribution 

 and dispersal. The Floridian fauna also includes a considerable ele- 

 ment of species that belong to groups with centers of distribution in 

 the Southwest, where they are generally adapted to more xeric 

 conditions than exist today on the coastal plain. The presence of 



