172 LIFE OF THE PLEISTOCENE 



Vallonia gracilicosta Helicina occulta 



parvula Galba caperala 



Polygyra hirsula " humilis madicella 



" monodon " obrussa 



" multilineata " reflexa 



" profunda Aplexa hypnorum 



Bifidaria armifera Pkysa gyrina 



" contractu " integra 



" penlodon Planorbis antrosus{ = bicarinatus) 



Vertigo ovala " trivohis 



" tridentata " dilalatus 



Vilrea hammonis " exactions 



Euconulus fulvus " parvus 



Zonitoides arborea Pisidium abditum 



" minuscula " compressum 

 Pyramidula cronhhilei anthonyi ( = striatella) Spkaerium simile ( = sulcatum) 



Helicodiscus parallclus Musculium truncatum 



Succinea avara Lampsilis anodonloides 



" ovalis Quadrula lachrymosa 



" retusa Eggs of small snails 



The remains of Bison bison have also been found in the alluvium at the 

 following localities: 



Jordan Township, Monona County, in bank of Beaver Creek. 



Hog Creek, Harrison County, in gully. 



The bones were associated with antlers and bones of the Virginia deer and 

 elk. An old beaver dam was found at a depth of twelve feet in the Monona 

 County exposure. Shells and bits of carbonized wood were also found with 

 the bones, which were buried to a depth of 15 feet in the Monona County 

 locality. 194 



Two miles east of Bellevue, 194a in a dark silty clay deposit in a low terrace, 

 six species of mollusks occurred. The deposit is believed to be referable to 

 post- Wisconsin time. 



Goniobasis nrginica Planorbis triiohis 



Campeloma decisa Planorbis antrosus( = bicarinatus) 



Pkysa heteroslropha Sphaerium slrialinum 



Of the above list, Goniobasis virginica is certainly an error, that species being 

 confined to the Atlantic drainage. It is possibly a lapsis pennae for Goniobasis 

 livescens, the common Mississippi Valley form of this genus. 



194 Shimek, Iowa Geol. Surv., XX, pp. 407-410. 



1Ma Shaw and Trowbridge, Galena-Elizabeth Folio, p. 7, 1916. 





