THE CHICAGO ACADEMY OF SCIENCES. 



stagnalis appressa. 

 columella. 



obrussa decampi. 



Jiumilis modicella. 



stagnates appressa. 

 columella chalybea. 

 caperata. 



humilis modicella. 



SPECIES IN 



stagnalis appressa. 



SAND AND GRAVEL DEPOSITS. 



caperata. palustris. 



humilis modicella. catascopium. 



obrussa. 



UNCLASSIFIED DEPOSITS. 



palustris. reftexa. 



FLORENCIA FORMATION. 

 LOESS. 1 



parva. 



humilis modicella. 



obrussa. 



obrussa. 



palustris. 



reflexa. 



obrussa. 



parva. 



SPECIES IN DEPOSITS 

 ASSOCIATED WITH MASTODON REMAINS. 



caperata. obrussa. 



DEPOSITS OUTSIDE ENGLACIATED AREA. 



MARL DEPOSITS. 



humilis modicella. obrussa. 



palustris. 



CHARCOAL ZONE, NEW MEXICO. 



bulimoides cocker elli. 



. - , > . ..... i . 



INTERGLACIAL BEDS. 



(Don Valley and Cayuga Lake.) 



palustris. catascopium. 



PLIOCENE BEDS. 



obrussa. 



UNCLASSIFIED DEPOSITS. 



humilis modicella. obrussa. 



palustris. 



DISTRIBUTION OF PRINCIPAL DEPOSITS IN WHICH FOSSILS 



OCCUR. 



ENGLACIATED AREA. 



Marl Deposits. Michigan, Wisconsin, Illinois, Indiana, South Dakota, 



Maine, Ontario, Canada. 



Clay Deposits. Illinois, Indiana, Ontario. 



Sand and Gravel Deposits. New York, Illinois, Ontario. 



Florencia Deposits. Illinois. 



Loess Deposits. Indiana, Illinois, Iowa, Nebraska, Kentucky, Ten- 



nessee, South Dakota, Missouri. 



Interglacial Deposits. Don Valley, Toronto and Cayuga Lake, N. Y. 



1 A number of Lymnseas have been reported from Loess deposits without 

 indication of the species. Such are found in Pacific R. R. Report, III, pt. 4, p. 

 22, 1856 (Red River, 26 miles above Fort Washita, Kansas); Owen's Survey of 

 Kentucky, p. 18, 1856; Safford's Geology of Tennessee, p. 434, 1869 (Shelby, 

 Tipton, Lauderdale, Dyer and Obion Counties); Broadhead, Amer. Geol., XXIII, 

 p. 395, 1904 (Missouri Loess). Several of these records may not be in true 

 Loess. 



