THE KANSAN ICE INVASION 283 



Cervidae 

 Odocoileus virginiamis (Zimm.) Rangifer species 



Rangijer, cf. muscatinensis Leidy Cervalces roosvelti Hay 



Bovidae 

 Bison lalifrons (Harlan) Symbos cavifrons (Leidy) 



occidentalis Lucas 



Elepantidae 



Elephas primigenins Blum. Mammut americanum (Kerr) 



" columbi Falconer* 



Casloroides ohioensis Foster 

 Sylvilagus floridanus (Allen > 

 Mephitis mephitica (Shaw) 

 Canus dims Leidy 



Castoroididae 

 Leporidae 

 mustelidae 

 Canidae 



IV. SUMMARY 



The deposits of the Yarmouth Interglacial interval are known to extend 

 from Nebraska and South Dakota eastward to southeastern Ohio, including 

 Illinois and Indiana; they extend south to the Missouri River in Missouri, 

 and to northern Kentucky; to the north they are found in Minnesota and 

 southern Manitoba, Saskatchewan, and Alberta. That the interval was of 

 long duration is believed by Leverett, 145 who states that the thickness of peat 

 and associated deposits is impressive evidence of an interglacial interval of 

 considerable length. The extent of the weathered zone is still greater proof. 

 Additional evidence of the long duration of this interval (in Iowa) is furnished 

 byKay, 145a who cites the great amount of weathering of the Kansan drift "which 

 produced a gumbo (gumbotil) over 20 feet in thickness, the diastrophic eleva- 

 tion of 150 to 200 feet, and the mature topography which was developed by 

 erosion after the diastrophism and apparently, in the main, before the close 

 of the Yarmouth epoch." 



Osborn 146 believes that the Yarmouth was the longest interglacial interval 

 and says of its climate: "It would appear that the Second Interglacial Yar- 

 mouth Stage was of greater duration than the entire interval between the Third 

 Glacial and the present time. In the course of this long warm Second Inter- 

 glacial Stage the climate again moderated, becoming slightly warmer than the 

 climate of today. The climate immediately following the retreat of the ice 

 was cool and moist, then followed a long warm stage, but this stage was finally 



1U Illinois Glacial Lobe, p. 43. 



««* Science, N. S., XL111, p. 398, 191 6. 



"* Men of the Stone Age, p. 269. 



