ICTIOBUS 67 



eye evidently closer to the angle of the preopercle than to the upper corner 

 of the gill-cleft; pharyngeal bones broad, but thin and weak, the teeth short 

 and compressed; vertebra? 36; air-bladder in two parts; dorsal fin long, with 

 from 25 to 30 rays, the anterior rays produced, about Yi the length of base 

 of fin, scales roundish; lateral line complete; color rather dark, never silvery; 

 sexual differences slight. 



Mississippi and Ohio rivers and their larger tributaries; three 

 species known, all of them common to our larger streams. These 

 fishes are the largest in size of the Catostomidce, not infrequently 

 reaching a length of 3 feet and a weight of 50 pounds. The name 

 " buffalo-fish " refers to the bull-like hump at the nape in old indi- 

 viduals. The relationships of these fishes with the carp are re- 

 mote. The view, not uncommon among fishermen, that carp and 

 buffalo interbreed is not supported by any facts in our knowledge, 

 and is probably based solely on the superficial* resemblance of the 

 buffalo and the carp in the form of the body and of the dorsal fin. 



The species are gregarious and nocturnal, coming out at 

 night on bars not frequented by them by day, and where they 

 may be readily reached by the seine. Fishermen report that 

 they move into lakes in cold weather, spending the winter as 

 much as possible in weedy water. They are said to dig holes in 

 the bottom, like the European carp. This genus includes closely 

 related species of identical general distribution in Illinois, but dif- 

 fering noticeably in respect to the structures of food selection, and 

 likewise to some extent in situations preferred, one of the more 

 abundant species especially (bubalus) habitually occurring in 

 deeper water than the other. In the red-mouth buffalo (cypri- 

 nella) the pharyngeal jaws are lighter than in bubalus, their teeth 

 have a smaller grinding surface, and the gill-rakers are longer 

 and more numerous. 



The feeding habits of the buffaloes, like those of all the fishes 

 inhabiting 'the muddy waters of central Illinois, are difficult of 

 observation, but several fishermen and other river men have re- 

 ported to us that these fishes have the habit of whirling around in 

 shallow water, or plowing steadily along with their heads buried 

 in the mud, their bodies in an oblique position, and their tails 

 occasionally showing above the surface. These operations have 

 nothing to do with the act of spawning, and probably indicate a 

 search for small mollusks and insect larvae living in the mud. 

 Buffaloes breed in the spring, depositing their eggs in great num- 



* The presence of the conspicuous maxillary barbels in the carp, entirely wanting in the 

 buffalo and the heavy serrated dorsal spine of the carp all fins of the buffalo being spineless 

 are sufficient marks of distinction. 



