270 FISHES. 



a. Lateral line complete ; body elongated ; angle of mouth 



usually with a small barbel. . HYBORHYNCHUS, 4. 

 aa. Lateral line incomplete ; body very short ; no barbels. 



PIMEPHALES, 3. 



ff Dorsal without spine, the rudimentary ray in front smaller 

 and firmly attached to the first developed ray. 



b. "With a small barbel (often very minute) at each angle of 



the mouth ; alimentary canal not longer than body ; teeth 

 hooked, without masticatory surface. 



c. Intermaxillaries not projectile, skin of lip and front 

 continuous; mouth rather inferior, beneath the promi- 

 nent snout; scales small, usually mottled; lat. 1. 60 to 

 70 ; sides rosy in Spring ; isthmus wide ; teeth 2, 4-4, 2. 



RHLNICHTHYS, 9. 



cc. Intermaxillaries projectile; species usually of larger 

 size or with larger scales. 



d. Mouth very wide, oblique; head broad, rounded; jaws 

 nearly equal ; the minute barbel just above the angle 

 of the mouth ; often a black spot on front base of 

 dorsal ; teeth 2, 5-4, 2. ... SEMOTILUS, 7. 



dd. Species usually of smaller size; the mouth rather 

 narrow and more or less inferior, with the small but 

 evident barbel at its angle ; no spot at base of dorsal ; 

 teeth 4-4 ; or 1 or 2, 4-4, 1 or 2. CERATICHTHYS, 8. 



J&. Angle of mouth without traces of a barbel. 



e. Mouth terminal, more or less oblique; the jaws about 

 even, or the lower somewhat projecting. (Upper jaw 

 sometimes swollen and projecting in spring males of 

 Luxilus and Semotilus.) 



f Anal with twelve or more developed rays ; body ele- 

 vated, abdomen compressed; lateral line greatly 

 decurved; mouth short, oblique; lower jaw rather 

 longest; dorsal behind ventrals; intestinal canal 

 long; teeth one-rowed, crenate, with masticatory 

 surface ; rather large species, with a silvery or golden 

 lustre NOTEMIGONUS, 21. 



jf. Anal with seven to eleven (rarely twelve) developed rays. 



