ECOLOGICAL NOTES ON THE MUSSELS OF 



WINONA, PIKE, AND CENTER LAKES OF 



KOSCIUSKO COUNTY, INDIANA. 1 



THOMAS J. HEADLEE. 



THE MUSSELS OF WINONA LAKE. 



During the summer of 1902 I became convinced that the 

 mussel fauna of Winona lake had a definite distribution, which 

 would repay careful study. I proposed, should circumstances 

 permit, to study this distribution and the conditions which control 

 it. The opportunity came the following summer and with the 

 aid of Mr. James Simonton, who had become interested in the 

 problem, the study was undertaken. 



We examined the bottom from four inches to four feet by 

 wading, from four to seven feet with a clam rake, from seven to 

 eighty-six feet with an iron dredge. 



The species found were determined by comparison with shells 

 that had been named by Call, Simpson, and Baker. The nomen- 

 clature is that used by Call in in his "Catalogue of the Mollusca 

 of Indiana," which was published in the Indiana Geological 

 Report for 1 899. They were : Unio lutcolus Lamarck, Unio 

 subrostralus Say, Unio glans Lea, Unio fabalis Lea, Unio nibi- 

 ginosus Lea, Anodonta grandis Say, Anodonta edcntula Say, 

 and Margaritana marginata Say. 



Winona is a deep kettle-hole lake. In general, the beaches 

 are composed of sand and gravel, which shade off with varying 

 rapidity into marly sand, then into sandy marl, then into coarse 

 white marl, and finally into the soft dark mud that covers the 

 bottom in all the deeper parts of the lake. The bottom steadily 

 grows softer as the proportion of dark mud increases. So soft 

 does it become that a small sounding-lead sinks into it of its own 

 weight from six to twelve inches. However, in some places, 

 especially the southwest side of the large lake and in nearly all 



1 Contribution from the Zoological Laboratory of Indiana University, No. 75. 



305 



