With a dark band along each side 



Hyhopsis amblops (Raf.) Bigeye Chub 



181. Eye very large, its diameter being more than one-third as long as the 



head; north-central states 



Erimystax dissimiUs (Kirtland) Spotted Shiner 

 Eye small; found in the region between the Mississippi and the Rockies 

 Macrhyhopsis aestwahs (Girard) Speckled Dace 

 Extrarius aesUvaUs (Girard) 



182. Pharyngeal teeth 6-6 or 6-5; no pseudobranchiae; scale count about 100; 



over a foot long; California 



Orthodon microlepidotus (Ayrcs) Blackfish 

 Pharyngeal teeth usually 5-5, 5-4, or 4-4 in the main row; with fewer 

 scales in most species 183. 



183. First ray of dorsal fin thickened and separated from the rest by a mem' 



brane (often difficult to distinguish); pharyngeal teeth 4-4; scale 



count usually under 50 184. 



First ray of dorsal fin slender and closely attached to the next 187. 



184. Peritoneum black; intestine more than twice as long as body; belly often 



appearing swollen 185. 



Peritoneum light; intestine less than twice as long as body; belly usually 



narrower 186. 



185. Lateral line more or less incomplete; with a faint to distinct dark lateral 



stripe; N. Y. to Texas 



Pimephales promelas Raf. Fathead 

 Lateral line complete; usually with a dark lateral stripe; Dakotas south 

 and east 



Hyhorhyyichus notatus (Raf.) Blunt-nosed Minnow 



186. Anal region with dark pigment; with a vertically oval dark spot on the 



base of the tail fin; Ozark region 



CeraUchthys tenellus (Girard) Mountain Minnow 

 Anal region unpigmented; with a round dark spot on the base of the tail 

 fin; central states to Okla. and Texas 



Ceratichthys vigilax B. & G. Bullhead Minnow 

 Ceratichthys perspicuus (Girard) 

 (Includes Cochlognathus ornatus B. ^ G.) 



187. Lower lobe of tail fin longer than the upper; snout like a pickerel's; 



pharyngeal teeth 4-5 or 5-5, thick, blunt, scarcely hooked; about three 

 feet long; Cal. and Oregon 



Mylopharodon conocephalus (B. fe? G.) Kaweah Chub, Hardhead 



Lobes of tail fin about equal or with the upper slightly longer than the 



lower; other characters various 188. 



188. With a sharp horny plate on each jaw; scale count about 85; pharyngeal 



teeth 4-5; about a foot long; northwestern U. S. 

 Acrocheilus alutaceus A. & P. Chiselmouth 

 Not so 189. 



189. Caudal peduncle very long and slender, almost round; pharyngeal teeth 



4-5 or 5-5; about a foot long; western species 190. 



279 



