420 ILLINOIS STATE ACADEMY OF SCIENCE 



Amnicola leightoni Baker, not common; somewhat 

 resembling some forms of liniosa. 



Amnicola tvalkeri Pilsbry, common and typical. 



Valvata tricariuata (Say), common and sliarply tri- 

 carinate. 



PJii/sa ivarreniana Lea, rare, but one young speci- 

 men f oimd. 



Galha elodes jolietensis (Baker), rare, one young 

 specimen f onnd. 



PisicUum spleudidulum (Sterki), rare. 



The above fauna is characteristic of a lake or large 

 pond and not of a swamp, and, probably represents a 

 former large body of water connecting one of the stages 

 of Glacial Lake Chicago. It is related in a general way 

 to the fauna of the marls of the Joliet quarry. 



STATION NO. 7. 



Locality : Bank of DuPage River, SE. 1/4 of NW. i^, 

 Sec. 10, T. 35 N., R. 9 E. 

 Material: Alluvial clay. 

 Stratigraphic horizon : Pre-recent. 



MOLLUSCAN LIFE 

 AQUATIC 



Gouiohasls livescens (Menke), common. 

 Campeloma suhsolidum (Anthony), rare. 

 Sphaerium stamineum (Conrad), rare. 



LAND 



Pyramidida solitaria (Say), rare. 

 Pyramidula aUernaia (Say), rare. 

 Polygyraliirsuia (Say), rare. 



This is a river fauna, the land mollusks being washed 

 in from the bank. The specimens are all normal and the 

 same species now live in the vicinity. 



