260 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. VII. 



aa. Anterior dorsal rays forming a stiff serrated spine; dorsal fin 



with 15 to 22 rays, 

 n. Mouth with 4 long barbels; scales in lateral series, 35 to 40; 



teeth 1,1, 3-3, 1,1. Cyprinus, 282 



nn. Mouth without barbels; scales in lateral series, 25 to 30; teeth 



4-4. Carassius, 283 



Genus Campostoma Agassiz. 



Body elongate, little compressed; mouth small, lips thick; pre- 

 maxillaries protractile; no maxillary barbel; pharyngeal teeth 4-4 

 or i, 4-4, o, with oblique grinding surface and a slight hook on one or 

 two teeth ; alimentary canal coiled around the air bladder ; peritoneum 

 black. 



Campostoma anomalum (Rafinesque). STONE-ROLLER. 



Head 4.0 to 4.6 ; depth 3.9 to 4.8 ; D. 8 ; A. 7 or 8 ; scales 46 to 53. 



Body elongate, subterete; head subconic, the snout projecting 

 beyond the mouth; mouth horizontal, the maxillary scarcely reaching 

 vertical from posterior nostril, its length 3.3 to 4.6 in head; eye small, 

 4.2 to 5.2 in head; snout 2.3 to 2.8; teeth 4-4 or i, 4-4, o, with 

 oblique grinding surface; origin of dorsal fin about midway between 

 end of snout and base of caudal; alimentary canal 5 to 9.5 times 

 length of body; peritoneum black; scales small, 15 to 26 in a series 

 between nape and dorsal fin, lateral line complete. 



Color brownish olive, sides irregularly blotched with darker; a 

 dusky vertical bar behind opercle, dorsal, and anal with a dusky bar 

 through the middle on males. 



Length 6 inches. 



This fish is abundant in small streams from Wyoming to New 

 York, North Carolina, and Texas. It prefers clear running water, 

 spawning on riffles in the spring. 



Bull Creek, Zion City, Illinois; Des Plaines River, Berwyn, Illinois; 

 Thorn Creek, Thornton, Illinois; Lockport, Illinois; Hickory Creek, 

 Alpine, Illinois; Hickory Creek, Marley, Illinois. 



Genus Chrosomus Rafinesque. 



Body moderately elongate, little compressed; mouth small, ter- 

 minal; lips normal; premaxillary protractile; no maxillary barbel; 

 pharyngeal teeth 5-5 or 4-5, moderately hooked tips, and with grind- 



