NORTH AMERICAN SPECIES OF THE GENUS ATAX 209 



at Dodge Creek, Emmet County, so that the species may be 

 accounted as generally distributed throughout the smaller in- 

 land lakes of Northern Michigan, and also in Lake Michigan 

 and the smaller lakes in connection with it, though present 

 nowhere in large numbers. Mr. Bryant Walker, a concholo- 

 gist and a member of the same party as the writer, turned over 

 to him two specimens of an Atax from Sphcervwm simile Say, 

 collected in "26 " Lake Aug. 6th, and on the 17th of Angust 

 specimens of adults and nymphs were secured in considerable 

 numbers from Anodonta footiana and Anodonta fragilis taken 

 in a lake at the north end of Beaver Island, Lake Michigan. 

 All of these have been carefully studied from mounts and the 

 author has been unable to detect any characters by which any 

 of them may be distinguished from Atax crassipes. 



Specimens were collected at Grand Rapids, Mich., during 

 the months of July and August, 1896 and 1897, in Reed's 

 and Fisk's Lakes, and in a third very small lake near the city. 

 The former are lakes of moderate size and with a depth of 20 

 meters or more, but the latter is hardly more than a pool in the 

 midst of a cranberry bog, 50 meters across, and with scarcely 

 more than a meter of clear water above the loose, half-floating, 

 semi-decayed vegetable mould which forms the bottom of such 

 lakes. All are spring-fed. Two specimens, apparently of this 

 species, were collected in two examples of Anodonta fragilis 

 from Reed's Lake, July 23, 1898. 



From Mr. J. B. Shearer have been received specimens col- 

 lected in Quannecussec River, an arm of Saginaw Bay, Lake 

 Huron, in the Kawkawlin River, an affluent of the same bay, 

 and at Les Chenaux Islands, in northern Lake Huron, near 

 Mackinaw, all obtained during August, 1895. 



In Wisconsin, the author has collected this form in Lake 

 Winnebago, at Oshkosh, Sept. 2, 1897, while he has received 

 it from two localities in Nebraska, — in a collection made by 

 Dr. H. B. Ward at a lake at South Bend, Sept. 2, 1897, and 

 from material obtained by Mr. O. D. Noble in a "stagnant 

 spring-fed pool" at Linwood, Sept. 1898. 

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