192 REPORT OF STATE GEOLOGIST. 



Genus ICTIOBUS. 



Bufalo-fishes and Garp-suGkers. 



Body deep and compressed. Mouth more or less inferior, protractile 

 downwards. Pharyngeal l)ones weak and furnished with numerous comb- 

 like teeth. Air-bladder in two parts. Dorsal fin long ; its rays about 

 thirty in number. Scales large ; about forty along the lateral line. Fon- 

 tanelle present between the parietal bones. 



A genus containing a number of sj)ecies which are not well defined, and 

 difficult of deterrriination. The flesh is of rather poor quality and full of 

 bones ; nevertheless, on account of the large size attained by many of the 

 species and their abundance in the larger streams, these fishes form an 

 important item in the food supply of people living along our rivers. 



ANALYSIS OF INDIANA SPECIES OF ICTIOBUS. 



A. Mouth moderate ; more or less oblique ; terminal, or nearly so ; 

 protractile forward and downward ; color dusky, not silvery, 

 and fins usually dark, 

 a. Mouth rather large ; terminal and protractile forward. 



eyprmella, p. 193. 

 aa. Mouth smaller and less terminal. 



b. Longest ray of dorsal not more than half the length of the 

 base of the dorsal fin. urus, p. 193. 



bb. Longest dorsal ray considerably more than half the dorsal 

 base. bubalus, p. 194. 



AA. Mouth small, inferior, protractile downward. Color paler and sil- 

 very ; fins not dark, 

 c. Form rather elongate ; depth three in length. 



carpio, p. 194. 

 cc. Form ovate ; the back arched ; depth about two and one- 

 half in length. 



d. Lips thick ; the halves meeting at an acute angle. 



velifer, p. 195. 

 dd. Lips thin ; the halves meeting at a large angle, 

 e. Snout very blunt ; eyes large ; four in head. 



diformis, p 195. 

 ee. Snout pointed ; eyes small ; five in head. 



thoinpsoni, p. 196. 



