30 CHECK LIST OF THE 



Genus ERIMYZON. (Chub Suckeks.) 



Body oblong, compressed ; head moderate ; mouth moderate, some- 

 what inferior, the upper Hp well developed, freely protractile, the lower 

 moderate, infolded, inversely V-shaped in outline, plicate with twelve to 

 twenty folds on each side; lower jaw without cartilaginous sheath, rather 

 stronger than usual, and oblique when the mouth is closed; eye moderate; 

 suborbital bones well developed, not much narrower than the fleshy part 

 of the cheek below them ; opercular bones moderately developed, not 

 rugose ; fontanelle rather large ; gill rakers rather long ; pharyngeal bones 

 weak; the teeth quite small, slender, and weak, rapidly diminishing in 

 length upward, each tooth narrowly compressed, with a cusp on the inner 

 margin of the cutting surface ; scales rather large, more or less crowded 

 forward ; no lateral line ; dorsal fin rather short and high, rays usually 

 eleven or twelve ; pectoral fins moderate ; anal fin high and short, more or 

 less emarginate or bilobed in adult males ; caudal fin moderately forked or 

 lunate, its lobes subequal. Air bladder with two chambers. 



(21) Chub Sucker. 



(Erimyzon sucetta.) 



Head rather short, broad above. Body oblong, rather deep, com- 

 pressed. Mouth rather small and but slightly inferior, protractile. Dorsal 

 short, rather high placed in middle of length ; caudal slightly forked ; no 

 lateral line. Scales, 43-15. 



D. , 12 to 15 ; A., 7 to 8. 



Colour dusky, brassy below ; young with black bands or bars and 

 pale streaks. 



Our form is probably E. sucetta oblongus. It reaches a length of 

 about ten inches and feeds on soft-bodied insects. 



Genus MINYTREMA. (Spotted Suckers.) 



Body rather elongate, subterete, becoming deeper and rather com- 

 pressed with age ; scales rather large and nearly uniform in size ; lateral 

 line interrupted in the adult, but with perfect tubes, imperfect in partly 

 grown specimens, and obsolete in the young; head moderate, rather broad 

 above; mouth moderate, inferior, horizontal; the upper lip well developed, 

 freely protractile; the lower rather small, infolded, inversely V-shaped in 

 outline, lower jaw without cartilaginous sheath ; eye moderate, rather 

 high, nearly median ; suborbital bones well developed ; opercular bones 

 well developed, not very rough ; fontanelle rather large ; gill rakers rather 

 long ; isthmus moderate ; pharyngeal bones essentially as in Moxostoma ; 

 dorsal fin rather short and high, inserted somewhat nearer to tip of snout 

 than to base of caudal; pectoral fins modernlo, pl;i(M-d low; anal high and 



