Lake Michigan in the Traverse Bay region. A nimiber of groups have been 

 studied qualitatively in Georgian Bay, for example the Ephemerida by 

 Clemens (19l5). 



The Hirudinea and Oligochaeta of the Great Lakes region have 

 been studied by Moore (1906) ; and a paper on the leeches of Ohio by 

 Miller (1929) considers those found in Lake Erie. Meehean (1929) re- 

 ported the presence of a marine annelid in Duluth Harbor, Lake Superior, 



A number of papers on the Mollusca of the Great Lakes have 

 appeared, and no attempt will be made to list all of them. The reader 

 will find extensive literature lists in reports by Baker (1920 and 

 1928), Osborn (1930), and Goodrich and Vander Schalie (1932). Ahlstrom 

 (1930) listed the molluscs found near the islands of Lake Erie. 



For papers on other groups of organisms in Lake Erie the reader 

 may refer to the bibliography compiled by Osborn (1930) , 



Almost nothing is known of the abundance of bottom organisms in 

 the Great Lakes, Adamstone (192U) reported on a series of seven Ekman 

 dredge samples taken in western Lake Ontario, and Sibley (1932) and 

 Farrell (1932) reported some results obtained near the east end of the 

 same lake. Cutler (1929) made a study of pollution along the shore at 

 the east end of Lake Erie but did not report the number of organisms 

 found. Osburn (1926 and 1926a) studied the question of pollution of the 

 bottom in parts of Lake Erie, including the part covered in the present 

 investigation. Unfortunately the animals in the dredge samples were not 

 counted. The report consists of notes on the character^jflif the bottom, 

 and the kinds and general abundance of the included organisms. Con- 

 sequently il is not possible to make detailed comparisons with the data 

 taken in the present study. However, it may be said that, as far as 

 comparisons can be made, the results obtained in the two investigations 

 are in close agreement. Since the completion of this survey, Krecker and 

 Lankaster (1933) published a report on the bottom fauna of the shores of 

 Western Lake Erie. 



Materials and methods 



The present report is based on qualitative and quantitative 

 samples taken in 1928, 1929, and 1930. For various reasons many of the 

 quantative samples for all three years were not used. Of those taken 

 in 1928, only 25. samples from 5 stations were incorporated in the 

 reoort. The season of 1929 is represented by I96 samples taken at lU 

 stations, and 1930 by 2l5 samples taken at 91 stations. Qualitative hauls, 

 made with a bottom sled (Helgoland trawl), numbered 2U in 1928 and 13 in 

 1929. Considering the large area covered, the number of samples taken 

 was small, yet they suffice to show some well-defined characteristics of 

 the bottom fauna, and justify certain conclusions with regard to abundance. 



250 



