78 ILLINOIS ACADEMY OF SCIENCE 



Galba palustris (Miiller). 

 Galba galbana (Say) 

 Galba obrussa decampi (Streng) 

 Galba obrussa exigua (Lea) 

 Lymnaea stagnalis apressa Say 



Of the above 25 species and varieties, 5 species formed about 

 90 per cent of the bulk of the material. These species are in- 

 dicated in the order of their abundance. 



Valvata tricarinata 

 Planorbis parvus 

 Amnicola lustrica 

 Paludestrina nickliniana 

 Galba obrussa decampi 



Lymnaea stagnalis appressa, Galba galbana, and Physa walkeri do not 

 live in the lake at the present time. This fauna probably migrated up the 

 St. Joseph River to the Dowagiac River and then up Dowagiac Creek. 



3. Pipestone Lake, Berrien County 



In the northeastern part of Berrien county, near the Van 

 Buren county line, is another lake of about the same area as 

 that of Magician Lake. This body of water drains into the 

 St. Joseph River through Pipestone Creek. Marl beds similar 

 to those of Magician Lake occur in Pipestone Lake, and have 

 yielded a number of species of mollusks as indicated below : 



Sphaerium simile (Say) 



Sphaerium striatinum (Say) 



Pisidium compressum Prime 



Pisidium variabile Prime 



Pisidium splendidulum Sterki 



Valvata tricarinata Say 



Amnicola limosa parva Lea 



Amnicola lustrica Pilsbry 



Physa integra Hald 



Physa heterostropha Say 



Planorbis trivolvis Say 



Planorbis antrosus Conrod 



Planorbis antrosus angistomus Hald 



Planorbis antrosus striatus Baker 



Planorbis campanulatus Say 



Planorbis deflectus Say 



Planorbis hirsutus Gould 



Planorbis parvus Say, many monstrosities 



Galba obrussa decampi (Streng) 



Galba obrussa exiqua (Lea) 



Lymnaea stagnalis appressa Say. 



These mollusks evidently migrated to Pipestone Lake either 

 by way of the Chicago outlet, the St. Joseph River and Pipe- 

 stone Creek, or up the Kankakee and St. Joseph rivers. It is 

 probable that both routes contributed to the formation of both 

 of these small lakes. 



My thanks are due to Dr. Bryant Walker of Detroit, Michi- 

 gan, and to Dr. V. Sterki of New Philadelphia, Ohio, for as- 

 sistance in identifying critical material. 



