Lake Maxinkuckee, Physical and Biological Survey 75 



92. Pyramidula perspective (Say) 



93. Helicodiscus parallelus (Say) 



94. Zonitoides arboreus (Say) 



95. Zonitoides nitidus (Miiller) 



96. Zonitoides minusculus (Binney) 



97. Euconulus fulvus (Miiller) 



98. Polita hammonis (Strom) 



99. Polita indentata (Say) 



100. Vallonia pulchella (Miiller) 



101. Vallonia costata (Miiller) 



102. Cochlicopa lubrica (Miiller) 



103. Strobilops labyrinthica (Say) 



104. Strobilops virgo Pilsbry 



105. Strobilops affinis Pilsbry 



106. Pupoides marginatus (Say) 



107. Pupilla muscorum (Linnaeus) 



108. Gastrocopta armifera (Say) 



109. Gastrocopta contracta (Say) 



110. Gastrocopta tappaniana (Adams) 



111. Vertigo rnorsei Sterki 



112. Carychium exile H. C. Lea 



113. Carychium exiguum (Say) 



114. Succinea retusa Lea 



115. Succinea obliqua Say 



116. Succinea avara Say 



THE CRUSTACEANS 



A comprehensive study of the Plankton was made by Professor 

 Chancey Juday now of the University of Wisconsin. A similar 

 thorough study of the Parasitic Copepods was made by Dr. Charles 

 B. Wilson whose report is made part of this paper. 



Except during the summer of 1899 and 1900 the field work on 

 Lake Maxinkuckee was nearly all done by one or two investigators 

 only. This made it impossible to pay equal attention to all the 

 groups of animals and plants; indeed, many groups could receive 

 scarcely more than passing notice, while others had to be wholly 

 neglected. Among those which received but slight attention are 

 the worms, polyzoans, protozoans, smaller crustaceans, insects, and 

 the like. Although considerable collections were made in some of 

 these groups, insurmountable difficulty was experienced in finding 

 specialists to work them up. Our reports on several of those 

 groups are therefore necessarily brief and general in character. 



