]3KA(50NFLIE8 OF THE DOUGLAS LAKE REGION, 



MICHIGAN ^ 



ARTHUR T. EVANS 



A partial list of the Odonata of the Douglas Lake Region (Gheboygan 

 County, Michigan) was prepared by Miss Abigail O'Brien in 1910'-. 

 This report includes twenty-three species. An oiiportunity of listing 

 the Odonata of this region more fully was affortled the writer during 

 the summer of 1914 while at the University of Michigan Biological 

 Station on Douglas Lake. The collections date from July 2 to August 

 21. During the course of the collecting as many individuals of each 

 species were taken as possible. Forty-three species were secured. 



The writer wishes to thank Professor Max M. Ellis for suggestions 

 in the preparation of this report; Professor Frank Smith for specimens 

 and records from Indian River; Professor T. D. A. Cockerell for the 

 loan of several reprints; and also the many students at the Biological 

 Station who were kind enough to furnish material foi' identification. 



TOPOGRAPHY OF THE REGION. 



The Douglas Lake Region with its small streams, lakes, marshes, and 

 stagnant bogs, together with its forested, burned over, and ()i)en areas 

 presents varied and suitable habitats for a number of species of Odonata. 

 Specimens were taken from many habitats, both adults and nymjihs 

 being collected. Efforts were made to capture a numlier of adults 

 which appeared new to the region. These efforts were unsuccessful 

 in several cases, but the aquatic collections yielded nymphs of several 

 species new to the region so that in all a fairly representative series of 

 the Odonata species w^as secured. Collections were made from the 

 following habitats. 



Bessey Creek, one of the small streams flowing into Douglas Lake, 

 forms a very desirable habitat for a number of species. This stream 

 is of uniform wadth, averaging about fifteen feet. It has an average 

 depth of about two and one-half f(H>t, with a maximum depth of about 

 five feet anil a minimum dei)tli of about one foot. For the most i)art 

 the stream flows through a thickly wooded area with trees overhanging 

 in many places while here and there are ojxmi areas. In many ])laces 



'Contribution No. 2.'S from the liiiversitv of Michigan Biological Station. 

 2Rept. Mich. Acad. Sci., I'.Ul, ]>\^. 114-145. 



