72 



FISHES OF ILLINOIS 



the principal species of each were the same as in cyprinella. The 

 Crustacea (13 per cent.) were almost all Entomostraca, a young craw- 

 fish taken by one of the buffaloes being the only exception. This 

 species had likewise eaten distillery slops and various forms of 

 aquatic plants, including duckweeds and unicellular algae. 



This buffalo spawned at Havana in 1898 between the 15th and 

 the 30th of April, but ripe females were caught the following year as 

 late as May 29. 



ICTIOBUS BUBALUS (Rafinesque) 



(small-mouth buffalo; razor-backed buffalo; 

 quillback buffalo) 



Rafinesque, 1818, J. Phj^s., 421 (Amblodon). 



G., VII, 22 (Sclerognathus urus); J. & G., 116 (Bubalichthys altus); M. V., 44; J. 

 & E., I, 164; N., 49, (cyanellus); J., 66 (Bubalichthys cyanellus); F., 82; F. F., 



II. 7, 448; L., 11. 



Body compressed, back 

 much elevated; ventral line not 

 much decurved ; back in front of 

 dorsal fin compressed into a 

 keel; depth from 2.5 to 2.9 in 

 length of body. Size somewhat 

 smaller than in the two preceding 

 species. General coloration 

 much as in cyprinella, but be- 

 coming paler in adults, sometimes 

 exceedingly so, old specimens 

 usually a muddy whitish, with 

 but faint traces of blue and 

 copperv about head and ante- 

 rior half of body; young speci- 

 mens usually quite dark, the 

 head dark bluish gray below; all 

 fins more or less dusky. Head smaller, more compressed, and more 

 pointed than in the foregoing species, the occipital region high and 

 sharply arched transversely, length of head 3.6 to 4.1, depth 4.4 to 5, 

 width 5.1 to 5.8 in bod}-^; interorbital space 2.1 to 2.6 in head; snout 

 pointed; mouth small, inferior, protractile downward and forward, 

 in size and form sometimes scarcely distinguishable froiu that of the 

 last species; lips rather coarsely and brokenly plicate; mandibles nearly 

 horizontal, scarcely forming an evident angle at the articulation with 

 the quadrate; eye 4.4 to 6.2 in head, rather larger than in either of the 

 preceding species ; opercle about as in last. Dorsal rays 2 7 to 30, the long- 

 est a little less than half base of fin; caudal somewhat more deeply forked 

 than in cyprinella or urus. Scales 7 or 8, 3 7-39, 5 to 7 ; lateral line coiu- 

 plete, gently flexuose. 



^ Head and snout of males finelv tuberculate in spring. 



Fig 16. 



