72 



FISHES OF ILLINOIS 



42 per cent. — but the principal species of each were the same as 

 in cyprineUa. The Crustacea (13 per cent.) were almost all 

 Entomostroca, a young crawfish 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 follow- 

 ing year as late as May 29. 



ICTIOBUS BUBALUS (Eafinesque) 



SMALL-MOUTH BUFFALO; RAZOR-BACKED BUFFALO; 

 QUILLBACK BUFFALO 



(Map XI) 



Rafinesque, 1818, J. Phys., 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., 



n. 7, 448; L., 11. 



Body compressed, back much 

 elevated; ventral line not much 

 decurvecl; 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 cyprineUa, 

 but becoming paler in adults, some- 

 times exceedingly so, old specimens 

 usually a muddy whitish, with but 

 faint traces of blue and coppery 

 about head and anterior half of 

 body; young specimens 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 body; interorbital space 2.1 to 2.6 in head; snout pointed; mouth 

 small, inferior, protractile downward and forward, in size and form some- 

 times scarcely distinguishable from 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 raj^s 27 to 30, the longest a little less than half base of fin; caudal 

 somewhat more deeply forked than in cyprineUa or urus. Scales 7 or 8, 

 37-39,5 to 7; lateral line complete, gently flexuose. 



Head and snout of males finely tuberculate in spring. 



Fig. 10 



