n i \u i;i S — CH \\ \ EL-C LTS 



177 



16 



Fig. I.'i I'l 



Premaxillary teeth of (46) Ameiurus melas (47) Leptops olivaris, 

 (48) Noturns flavus, and (49) Schilbeodes gyrinus. 



Genus ICTALURUS Kafinesque 



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 form- 

 ing a continuous bony bridge from the head to the dorsal spine. Mouth 

 small, terminal, the upper jaw longer. Teeth subulate, 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. Coloration 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) . Thej T 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 A 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 ft 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. 



