APRIL, 1910. FISHES OF CHICAGO MEEK AND HILDEBRAND. 249 



cc. Lips papillose; air bladder in 2 parts; scales 48 to no. 



Catostom us, 255 



Genus Ictiobus Rafinesque. 



THE BUFFALO FISHES. 



Body robust, compressed, both dorsal and ventral outlines curved ; 

 head rather large; mouth terminal or slightly inferior; lips thin, 

 plain or more or less plicate; the upper protractile downwards and 

 forwards; eye nearer angle of preopercle than upper corner of gill 

 cleft; pharyngeal bones broad, but thin and weak; the teeth long; 

 dorsal fin long, of 25 to 30 rays; the anterior ones produced to about 

 ^2 length of fin; air bladder in 2 parts; lateral line complete; colora- 

 tion dark, never silvery. All are good food fishes. 



a. Body slender, the dorsal region little elevated, depth 3.0 to 3.5 



in the length. urus, 249 



aa. Body deeper, the dorsal region elevated; depth 2.5 to 2.8 in 



length. bubalus, 249 



Ictiobus urus (Agassiz). MONGREL BUFFALO. 



Head 3.7 to 4.0; depth 3.0 to 3.4; D. 29 or 30; A. 9 or 10; scales 



36 to 40. 



Body robust, the dorsal and ventral outlines about equally curved; 

 snout bluntly rounded; mouth small, little oblique, protractile down- 

 ward and forward, lips plicate; eye small, 5.1 to 6.6 in head; inter- 

 orbital space 2.0 to 2.3 in head; tips of anterior rays of dorsal when 

 deflexed not reaching past middle of fin ; lateral line complete. 



Color dark slaty-gray to almost black; fins all dark. 



This fish reaches a weight of 50 pounds but those usually seen in 

 the market seldom exceed 10 pounds. 



It inhabits the larger streams and bayous throughout the Mississippi 

 Valley, the southern end of Lake Michigan and the tributary streams. 

 It spawns in April. 



Lagoon, Jackson Park, Chicago, Illinois. 



Ictiobus bubalus (Rafinesque). SMALL-MOUTH BUFFALO. 



Head 3.6 to 4.1; depth 2.5 to 2.9; D. 27 to 30; A. 9 to 10; scales 



37 to 39. 



Body robust, the dorsal region considerably elevated; snout 

 bluntly pointed; mouth small, inferior, protractile downward and 

 forward; lips coarsely and brokenly plicate; eye small, 4.4 to 6.2 in 

 head; interorbital space 2.1 to 2.6 in head; tips of anterior rays of 

 dorsal when deflexed not reaching middle of fin ; lateral line complete. 



