58 



VERTEBRATE ANIMALS OF THE UNITED STATES 



T. rhothceca (Thoburn). Length 125 mm.; color olive, with a black 

 lateral stripe and black crossbars; scales 7-48-5; rays of dorsal lin 11; 

 of ventral 8: Atlantic slope of Virginia. 



10. Xyrauchen Eigenmann & Kirsch. Like Catostomus, except that 

 immediately behind the head is a very prominent, sharp-edged hump; 

 snout blunt: i species, 



A', iexanus (Abbott). Razor-back. Head and depth 4; rays of 

 dorsal fin 13 or 14; anal 7; scales 13 to 15-72 to 77-13; color olivaceous: 

 Colorado basin; abundant. 



11. Erimyzon Jordan. Body fusiform, compressed; scales large; 

 lateral line wanting: i species. 



Fig. 28. — Erimyzon siicetla {from Jordan b' Evermann). 



E. sucetta (Lacepede). Chub sucker (Fig. 28). Length 250 mm.; 

 head 4.25; depth 3; color dusky, with a coppery lustre; young with a 

 broad black lateral band or series of blotches; rays of dorsal fin 1 1 to 12 ; 

 anal 7; scales 36-15, in southern specimens, but 43-15 north of Virginia: 

 Great Lakes region; Mississippi Valley; coastwise from Virginia to 

 Texas; very common. 



12. Minytrema Jordan. Body elongate, little compressed, with an 

 interrupted lateral line in the adult, and a small black spot at the base 

 of each scale on the side: i species. 



M. melanops (Rafinesque). Spotted sucker. Length 600 mm.; 

 head 4.3; depth 3 to 4; color dusky above, with usually a black blotch 

 behind the dorsal fin; rays of dorsal fin 1 2 to 14; anal 7 ; scales 44 to 47 : 

 Great Lakes to Florida; upper Mississippi Valley to Texas; common. 



13. Moxostoma Rafinesque. Redhorse. Body elongate; mouth 

 inferior; lips well developed, with transverse folds (Fig. 29); jaws with- 

 out cartilaginous sheath ; upper lip protractile ; scales large ; anal fin 



