ICTALURUS CHANNEL-CATS 



177 



Fig. 46-49 



Premaxillary teeth of (46) NoUirus flavus, (47) Leptops olivaris, 

 (48) Schilbeodes gyrinus, and (49) Ameiurus melas. 



Genus ICTALURUS Rafinesque 

 (channel-cats) 



Body elongate, slender, compressed posteriorly. Head typically 

 slender and conical; broad in a single species, anguilla, which approaches 

 the genus Ameiurus. Supraoccipital process produced backward, its 

 emarginated end receiving the acuminate anterior point of the second 

 interspinal, thus forming a continuous bony bridge from the head to the 

 dorsal spine. Mouth small, terminal, the upper jaw longer. Teeth sub- 

 ulate, in a short band on each jaw. Anal fin long, with 25 to 35 rays. 

 Caudal fin elongate, more or less deeply forked, the lobes pointed. Color- 

 ation usually pale, bluish olive to silvery. 



Fresh waters of North America ; 4 species known, all being large, 

 more or less active, species of the river channels.* These are the 

 true "catfishes," in distinction from the bullheads {Ameiurus) and 

 the mud-cat {Leptops). They are the best of the family as food. 



Key to the Species of ICTALURUS found in Illinois 



a. Anal fin of from 30 to 35 rays, including rudiments, its free margin nearly 



straight; eye low, nearer lower than upper surface of head; color bluish or 



silvery, usually without specks furcatus. 



aa. Anal fin shorter, of 24 to 29 rays, including rudiments, its free margin 

 rounded ; eye above median axis of body, nearer upper than lower surface 

 of head. 



b. Head small, slender, subconic, its greatest width about -^xj of its length; 



dorsal fin high and pointed, the longest ray about % of head; color bluish 

 olive to silvery, always more or less spotted with darker punctatus. 



bb. Head large, broad and heavy, its greatest width nearly -^^ of its length; 

 dorsal fin low and more or less rounded, its longest ray little more than 

 + of head; color slaty olive to yellowish anguilla. 



*This statement is not well known to apply to /. anguilla. 



