232 LIFE OF THE PLEISTOCENE 



Hay (Iowa Geol.' Surv., XXIII) adds the following data concerning the 

 vertebrate fauna of Iowa: 



Lee Countv, Montrose. Tooth of Equtcs niobrarensis at depth of 25 feet 

 (p. 77). 



Pottawattamie County, near Oakland. Incisor tooth of Castoroides 

 ohioensis from sand in Nishnabotna River (p. 82). 



Lyon County, Doon. Tusks of proboscidian in gravels, 25 feet below the 

 surface (p. 83). 



Mahaska County, near Oskaloosa. Right innominate bone of probosci- 

 dian, brot from bed of Skunk River by hook of fisherman (page 440), possibly 

 Aftonian. 



Leighton 52a records Aftonian wood fragments in a soil zone beneath Kansan 

 till, in new cuts on the C. M. & St. P. Ry., in the vicinity of Delmar Junction. 



2. Nebraska 



In Nebraska, the Aftonian stage has been identified in Douglas County, 

 good exposures occurring at Omaha, where Equus and Elephas imperator have 

 been found, as well as at Council Bluffs, just across the river. 53 In a cut near 

 Hartington, Cedar County, 54 the Kansan drift rests upon a calcareous marl 

 from which the following mollusks have been identified: 



Valvata tricarinata Planorbis parvus 



Galba obrussa (=desidiosa) Succinea obliqua (=0Dalis) 



" palustris (imperfect specimen) Sphaerium striatinum 



Todd also describes a "volcanic ash" stratum beneath drift, five or six 

 miles south of Santee, Knox County. Beneath this stratum is a bed of lami- 

 nated clay containing a multitude of the shells of Limnophysa desidiosa {= Gal- 

 ba obrussa)? b Hay {op. cit., page 141) records Mylodon harlani? from Tecum- 

 seh, Johnson County. 



3 . Missouri 



In Missouri, several deposits occur which should apparently be cor- 

 related with the Aftonian stage. Three are well within the area covered by 

 the Kansan drift sheet, the balance are near the southern limit of the drift. 

 Bain 56 records a forest bed nine feet in thickness and 120 feet below the surface 

 in Harrison- County; McGee" mentions a forest bed in Macon County; and 



" a Science, N.S., XLIV, p. 68, 1916. 



53 Shimek, Geol. Iowa, XX, p. 308, XXI, p. 138. 



64 Todd, Bull. 158, U.S. Geol. Surv., p. 73. 



"Op. cit., p. 70. 



58 Geol. Iowa, VIII, p. 290. 



57 Trans. Acad. Sci. St. Louis, V, pp. 305-336. 



