28o Field Museum of Natural History — Zoology, Vol. VII. 



Genus Seiiiotiliis Rafinesque. 



Fallfishes. 



Body robust; mouth terminal ; premaxillary protractile ; a small 

 barbel on upper side of maxillary near its extremity; teeth 2, 5-4, 2, 

 hooked and without grinding surface ; alimentary canal less than twice 

 the length of the body; peritoneum pale; scales 45 to 60 in lateral 

 series. 



Semotilus atromaculatus (Mitchill). Horned Dace; Creek Chub. 



Head 3.5 to 3.9; depth 4.1 to 4.6; D. 8; A. 8; scales 55 to 69. 



Body elongate, robust anteriorly; head large, broadly rounded 

 above; mouth large, terminal, oblique, tip of upper lip on level with 



Fig. 45- Horned Dace; Creek Chub. 



Semotilus atromaculatus (Mitch.). (From Forbes and Richardson.) 



lower margin of pupil; maxillary reaching beyond anterior margin 

 of orbit, its length 2.9 to 3.4 in head; diameter of eye 4.8 to 7.1 in 

 head; teeth variable, usually 2, 4-5, 2, the shorter row may have o, 

 I or 2, the longer one 4 or 5 teeth; alimentary canal about length of 

 body; peritoneum pale; lateral line complete; scales smaller on an- 

 terior portion of body, about 35 rows in a series before dorsal fin. 



Color dusky bluish above to silvery below; a faint dark lateral 

 band usually ending in a dark caudal spot; dorsal fin with a distinct 

 dark blotch at base of first rays. 



Length about 6 to 8 inches. 



This species ranges from Wyoming to Maine, North Carolina, and 

 Missouri. 



Bull Creek, Zion City, IlHnois; Bull Creek, Beach, Illinois; Petti- 

 bone Creek, North Chicago, Illinois; Ravine, Glencoe, lUinois; Thorn 

 Creek, Thornton, Illinois; Butterfield Creek, ElHotts Park, Illinois; 

 Hickory Creek, Alpine, Illinois; Hickory Creek, Marley, Illinois. 



