ICTIOBUS 



69 



region white dulled with bluish; predorsal region and upper part of caudal 

 peduncle slate; dorsal and caudal fins drab-gray; anal dusky olive; ventrals 

 lighter; pectorals dull white under olive. Head large and heavy, its length 

 from 3.3 to 3.7, depth 3.9 to 4.2, width 4.8 to 5.2 in length of body; snout 

 blunt and broadly rounded; inter- 

 orbital space convex, 2 to 2.4 in 

 head; snout separated from frontal 

 region of head by a slight trans- 

 verse depression in front of orbits, 

 giving it a turned-up appearance; 

 mouth large and wide, terminal, 

 protractile forward, very oblique, 

 upper edge of mandible about 

 reaching level of median axis, upper 

 lip almost on a level with lower mar- 

 gin of orbit; mandibles strong and 

 broad, forming a wide protruding 

 angle at their union with the 

 quadrate; lips thinner and smoother 

 than in other species of Ictiobus, 

 upper very thin and nearly smooth, FIG. 14 



lower thicker and somewhat lobed 



at corners, rather faintly and finely striate; eye 5.6 to 7 in head, situated 

 well forward; opercle strongly striated and very broad. Dorsal rays 24 to 

 28, longest ray a little more than half the base of fin; caudal not deeply 

 forked; anal short, inserted under last rays of dorsal; ventrals falling about 

 as short of vent as pectorals do of ventrals. Scales large, uniform in size 

 and evenly distributed, rather loosely imbricated, their number 7 or 8, 37 

 to 40, 6 or 7 ; lateral line complete, rather flexuose posteriorly and somewhat 

 abruptly elevated in front of dorsal fin. 



Sexual differences slight, the males averaging a little smaller in size and 

 darker in color than the females; spring males without tubercles. 



Distributed throughout the Mississippi Valley, in rivers, 

 lakes, ponds, and larger creeks; also in the Red River of the 

 North to Winnipeg. It does not occur east of the Alleghanies, 

 nor in the Great Lakes. 



This is a very abundant fish in our larger streams and in the 

 lakes of the river bottoms, being one of the three species most 

 commonly shipped from the Illinois and the Mississippi under the 

 name of " buffalo-fish." It is taken abundantly in the latter 

 river at Cairo, Grafton, and Quincy, and is one of the important 

 commercial species of the Illinois, from which it is caught in large 

 numbers as far north as Henry. It is much less abundant now, 

 however, than some years ago. It is the common "buffalo-fish" 

 of the fishermen, and generally receives no more distinctive 

 name. It grows to a large size, sometimes reaching a weight of 



