80 FISHES OF ILLINOIS 



terminal and somewhat oblique, the tip of the lower lip far in advance of 

 the nostrils; lips evidently plicate, not very thin, the halves of the lower 

 one meeting at a rather wide angle; interorbital space 2.4 to 2.7 in head; 

 eye small, 5 to 6.4, usually more than 5.5. Dorsal rays 25 to 30, usually 

 nearer 30, anterior rays slender, little elevated, scarcely more than half the 

 length of base of fin. Scales somewhat smaller and more closely imbricated 

 than in the two preceding species, 7, 38 to 40, 6, usually 39 in longitudinal 

 series; lateral line complete, nearly straight. 



FIG. 20 



This species can be separated with readiness from both the 

 preceding by its longer nose, more oblique mouth, and more 

 posterior nostrils; it is easily distinguished from the next when 

 adult by its larger size and by the differences in general propor- 

 tions, and by the shortness of the first dorsal rays. The young 

 of these two species can not be separated with any certainty. 



This carp-sucker belongs to the fauna of the Great Lake 

 region and is but rarely taken in the inland waters of Illinois, 

 our adult specimens numbering a very few from the Illinois 

 river at Ottawa, Henry, Havana, and Meredosia. It is too 

 rare in our waters to be commercially important. Its special 

 habits are unknown. 



GENUS ERIMYZON JORDAN 



CHUB-SUCKERS 



Body oblong, more or less compressed; mouth subinferior; upper lip 

 protractile; lower lip plicate, infolded, forming an acute angle in front; no 

 anterior fontanelle; posterior fontanelle well developed; no supraorbital 

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



