54 



of Sciences or by loaning material for study: Professor W. K. 

 Higley, T. Jensen, John Henry, A. W. Conner, J. D. Hood, 

 Thomas Swick, Carl Dilg, W. W. Calkins, W. W. Cooper, F. M. 

 Woodruff, H. B. Derr, Dr. H. N. Lyon, H. Fischer, E. W. Engle- 

 holm, R. L. Rea, and James Zetek, of Chicago; J. H. Ferriss, J. H. 

 Handwerk, and Mr. Oakes, of Joliet; E. Chamberlain and V. H. 

 Chase, Wady Petra; Benjamin T. Gault, Glen Ellyn; L. E. Dan- 

 iels, La Porte, Indiana; and Mrs. E. C. Wiswall, Kenosha, Wis- 

 consin. Collections made by Robert Kennicott, E. W. Nelson, 

 and J. W. Velie are in the collection of the Chicago Academy 

 of Sciences, and have been used in preparing this catalogue. 



The following gentlemen have kindly identified the groups 

 indicated, and my thanks are due to them: Dr. H. A. Pilsbry, 

 Academy of Natural Sciences, Philadelphia, Penn., various land 

 and fresh-water shells; Mr. Bryant Walker, Detroit, Mich., 

 Ancijll and other fresh-water shells; and Dr. V. Sterki, New 

 Philadelphia, Ohio, Corneor//cl(ts and Pupidce. These gentlemen 

 have also identified considerable material in the State Labora- 

 tory collection. 



My thanks are especially due to Prof. S. A. Forbes, Director 

 of the State Laboratory of Natural History, Urbana, for the priv- 

 ilege of studying and listing the very large collection of Illi- 

 nois mollusks under his charge. 



This catalogue is but a tentative list, and additions and 

 corrections are earnestly solicited from all interested persons. 



In the following pages the writer has aimed to present a 

 condensed survey of our knowledge concerning the molluscan 

 fauna of the state of Illinois. The position of the state, lying, 

 as it does, with the Mississippi River on the west, the Wabash 

 River on the east, the Ohio River on the south, and Lake Michi- 

 gan on the north, not to speak of the Illinois, Kaskaskia, Rock, 

 and other rivers intersecting the state, is particularly favorable 

 to the presence of a varied and abundant molluscan fauna. The 

 rich woodlands bordering or near the watercourses also afford 

 favorite retreats for the terrestrial species, about one sixth of 

 the surface being forest-covered. 



