6 University of MicJiigan 



1920, 18 mi. E 5/2 S and on May 26, 1922, 8 mi. NE of Port 

 Washington ; on September 28, 1920, 5 mi. and 40 mi. SE x E 

 and on October i, 1920, 11 mi. SE of Sheyboygan; on August 

 24, 1920, 10 mi. E X N of Algoma; on August 23, 1920, 12 mi. 

 E X S of the Sturgeon Bay Ship Channel mouth ; on August 18, 

 1920, 3 to 5 mi. WNW of Boyer Bluff, and on August 

 19, 1920, 20 mi. E /^ N of Rock Island. Other specimens, not 

 designated as paratypes, and not involved in the description of 

 the species, were collected in Lake Michigan off the Michigan 

 shore on August 12, 1920, 15 mi. SE x S ^ S of Manistique; 

 on June 29, 1920, 5 mi. N x E, on June 30, 1920, 3 mi. NW, on 

 June 15, 1923, 22 mi. NNE-and on August 11, 1923, 3 mi. NW 

 y2 W of Charlevoix; on August 10, 1923, 8 mi. NNW of Big 

 Rock Point, and on August 21, 1923, from an unknown loca- 

 tion off Charlevoix ; on June 22, 1920, 5 mi. NNW and on 

 July 31, 1923, 5 mi. NW of Cat Head Point; on June 23, 1920, 

 off Northport Point; on October 4, 1920, 9 mi. north of Point 

 Betsie; on August 27, 1920, 4 mi. west, and on August 28, 1920, 

 9 mi. NW of Manistee. Still others were collected in Lake 

 Ontario, in New York waters off Wilson, Sodus Point, Os- 

 wego, Selkirk and Sandy Pond, and in Canadian waters off 

 Brighton; in Lake Superior off Grand Marais, Minnesota, and 

 at several locations on the Ontario shore between Fort William 

 and Rossport, and also in Lake Nipigon. 



The body is little compressed, much less than in any other 

 member of the genus, excepting artcdi, and as seen from the 

 side, tapers smoothly and regularly to the head and tail from 

 the deepest portion of the body which is through a point at the 

 front of the dorsal. This dimension is in the type 23%, in most 

 of the other adult specimens at hand 22-26%, of the length. 

 Occasionally an individual is taken in which this figure rises to 

 29% and in such specimens the predorsal body profile is steeper 



