92 VERTEBRATE ANIMALS OF THE UNITED STATES 



Ci Complete bony ridge extending from the head to the dorsal 



fin I. Ictaliirus. 



C2 Bony ridge from head to dorsal fin interrupted 2. Anieiurus. 



bo Rays of anal fin 1 2 to 1 5 3. Leptops. 



do Posterior margin of anal fin adnata to back. 



bi Adipose fin separated from caudal fin by a distinct notch. . . .4. Noturus. 

 bj Adipose fin either not separated from the caudal fin or sepa- 

 rated only by a slight notch 5. Schilheodes. 



I. Ictalurus Rafinesque. Channel cats. Body slender; head 

 conical; mouth small; supraoccipital process prolonged posteriorly, 

 its emarginate end receiving the anterior tip of the second interspinal, 

 thus forming a continuous bony ridge between the head and the dorsal 

 fin; rays of dorsal fin usually I, 6; caudal fin deeply forked; 8 barbels 

 present: 4 species, i in Gautemala, all important food fishes. 



Key to the United States Species of Ictalurus 



ai Body not spotted. 



bi Anal fin with 32 to 35 rays /. furcatus. 



b2 Anal fin with 24 to 26 rays /. anguilla. 



a.2 Body spotted /. punctatus. 



I. furcatus (LeSueur). Great forked-tail cat (Fig. 39). Extreme 

 length 1,500 mm.; extreme weight 150 lbs.; average weight 10 lbs.; 

 head 4.5; depth 4; color silvery; anal fin almost one third the length 

 of the body: Mississippi Valley and Gulf States; northward to Iowa 

 and Ohio; abundant in the south. 



Fig. 39. — Anal and caudal fins of Ictalurus furcatus {from Fishes of Illinois). 



I. punctatus (Raf.). Channel cat; spotted cat (Fig. 40). Extreme 

 length 600 mm.; extreme weight 25 lbs.; head 4; depth 5; color oli- 

 vaceous, with small irregular round black spots; anal fin with 25 to 

 29 rays: Great Lakes, Gulf slope and Mississippi Valley regions; gener- 

 ally abundant in the channels of large streams. 



