THE KANSAN ICE INVASION 253 



Polygyra profunda Galba humilis modicella 



" multilineata (small form) 



A fossiliferous Kansan loess occurs in the bluff above Hershey Avenue, 

 Muscatine, which contains a varied molluscan fauna. Leverett 28 quotes the 

 subjoined list, after Udden. 



Eelicina occulta Cochlicopa lubrica 



Polygyra multilineata (young, probably Pyramidula alternata 



this species') perspectiva 



" monodon cronkhitei anthonyi 



Strobilops virgo Succinea avara 

 Bifidaria pentodon " obliqua 



Pupilla blandi (listed as muscorum 29 ) Galba caperala 



" muscorum {vide Shimek 29 ) Valvata sincera 



The Valvata evidently belongs to an earlier period than the loess, when 

 fluviatile conditions prevailed in the Yarmouth stage. It may also have been 

 artifically introduced at a later stage. The species is questionable, the name 

 sincera formerly embracing several species, as lewisii, bicarinata perdepressa, 

 etc. 



McGee 30 has published a list of loess fossils from Muscatine, furnished by 

 Prof. Witter, which contains several species not included in the Udden and 

 Leverett lists. These are: 



Helix fulva (=Euconulus fulvus) 



" ptdckella ( = Vallonia gracilicosta?) 

 Pupa quarticaria (= Bifidaria corticarid) 



" simplex (=Sphyradium edentulum allicola) 



It is not known from just what horizon Witter's shells were secured and 

 the list is therefore not available for use in the present connection. The five 

 naiades listed (which are referred to later) belong to a later period. 



At Davenport, two loesses occur above the Yarmouth deposits, one, the 

 lower, post-Kansan (bluish-gray) and the other, the higher (yellowish in color) 

 post-Dlinoian, the interval between marking the presence of the Illinoian ice 

 sheet. The post-Kansan loess contains the following species: 31 



Succinea obliqua Leucockila fallax 



" avara Pyramidula cronkhitei anthonyi 



Eelicina occulta 



The tusk and molars of a mammoth were found in the upper part of the 

 loess, at its junction with the post-Illinoian loess. It may possibly belong to 



28 Illinois Glacial Lobe, p. 174. Modern names are here used. 

 " Shimek, Amer. Geol., XXVIII, p. 346. 

 20 11th An. Rep. TJ. S. Geol. Surv., p. 471. 

 31 Pratt, Proc. Daven. Acad. Sci., I, p. 97. 



