288 LIFE OF THE PLEISTOCENE 



At Davenport, in Scott County, Leverett records the presence of a p'ost- 

 Illinoian loess. Near the base of the loess at Division Street, eight species of 

 mollusks were secured by Prof. Udden: 10 



Helicina occulta Bifidaria pentodon 



Succinea avara Galba palustris 

 Sphyradium edenlulum alticola " caperata 



Pyramidula cronkhilei anthonyi Sp1iaerium-iTa.gvae.nt of valve 



Udden's first list differs somewhat {op. cit., p. 168) and may have been based 

 on specimens from a higher position in the loess. 



Succinea avara Pyramidula cronkhilei anthonyi 



" grosvenorii Helicodiscus parallelus 



" luteola Helicina occulta 



CocUicopa lubrica Sphyradium edentidum alticola 



In a cut along the Chicago, Rock Island and Pacific Railroad, west of 

 Davenport, the tusk, teeth, and other bones of Elephas primigenius were found 

 in a bed of bluish loess (post-Illinoian) 3-5 feet thick which lay just above a 

 bed of brown peat (Sangamon soil) 1 foot in thickness. This deposit has been 

 thot to be Aftonian, but seems clearly post-Illinoian. 10a 



Mammoth bones, apparently referable to the Sangamon, have been found 

 at Big Rock and Blue Grass, Scott County. The latter was buried 10 feet 

 below the surface, embedded in yellow clay. 11 



At Muscatine, Muscatine County, fossiliferous deposits occur which are 

 referable to the Sangamon interval. McGee 12 lists the following fauna: 



Fusconaja ebena Pupilla blandi 



Nephronajas ligamentina Bifidaria corticaria 

 Eurynia recta " pentodon 



Arcidens conjragosus Sphyradium edentidum alticola ( = simplex) 



Campeloma subsolidum Helicodiscus parallelus {=lineata) 



Helicina occulta Pyramidula cronkhilei anthonyi (= striatella) 



Galba humilis modicella Oreoltelix iowensis ( = ' cuperi' = cooper i) 



Succinea ovalis Euconulus fulvus 



" avara Vallonia gracilicosla ( = pulchella) 

 Pupilla muscorum 



The four naiades as well as the Campeloma listed above, probably came 

 from a fluviatile stratum beneath the true loess, probably formed at a time 

 when the Mississippi was at a much higher level than at present. 



10 Illinois Glacial Lobe, p. 173. 



1,a Pratt, Proc. Daven. Acad.Sci.,l,p.96; Norton, Iowa Geol. Surv., IX, p. 482; Shimek, 

 op. cz'/.,XX,p. 376. 



11 Anderson, Augustana Library Pub., No. 5, p. 35. 



12 11th An. Rep. U. S. Geol. Surv., p. 471, after Witter. The modern nomenclature is 

 here used. 





