256 Field Museum of Natural History — Zoology, Vol. VII. 



scales on sides and upper part of body reduced in size anteriorly; 

 lateral line complete; caudal forked. 



Color olivaceous above, lighter below; sides of male in breeding 

 season with a broad rosy band. 



Length about 24 inches. 



This species inhabits the Great Lake Region, the Upper Missouri 

 and Columbia Rivers, and northward into Alaska. Frequently taken 

 by fishermen at Pine and Millers, Indiana. Not abundant and of 

 little value as a food fish. 



Lake Michigan, Millers, Indiana; Lake Michigan, Pine, Indiana. 



Catostomus commersonii (Lacepede). Common Sucker. 



Head 4.0 to 4.8; depth 4.3 to 5.3; D. 11 to 13; A. 7; scales 63 to 

 80. 



Body elongate, subterete, robust anteriorly; head subconical, 

 flattish above; interorbital space nearly flat; 2.1 to 2.6 in head; 

 snout blunt; mouth inferior, the lips strongly papillose; the diameter 

 of eye 4.5 to 6.8 in head; scales smaller on anterior portion of body; 



Fig- 27. Common Sucker. 



Catostomus commersonii (Lac). (After Forbes and Richardson.) 



lateral line complete in adults, partially absent in the young; caudal 

 fin forked. 



Color olivaceous on back and sides; lighter below; spring males 

 with a faint rosy lateral band. 



Length about 18 inches. 



This species inhabits the smaller streams from Georgia to Missouri 

 and northward to Great Bear Lake and Hudson Bay. Spawns in 

 the spring. Too full of small bones to be of much value as a food fish. 



Fox River, McHenry, Illinois; Bull Creek, Zion City, Illinois; 

 Bull Creek, Beach, Illinois; Pettibone Creek, North Chicago, Illinois; 

 Ravine, Glencoe, Illinois; Jackson Park, Chicago, Illinois; Des 

 Plaines River, Chicago, Illinois; Thorn Creek, Thornton, Illinois; 

 Hickory Creek, Alpine, Illinois; Hickory Creek, New Lenox, Illinois; 



