44 TELEOSTEI : EVENTOGNATHI. — XII. 
hh. Mouth singular, the upper lip not protractile, greatly enlarged; 
the lower split into two separate lobes; pharyngeal bones, etc. 
asin Moaostoma. . . . + + + + + « « LaGOcHILA, 48. 
41. ICTIOBUS Rafinesque. BurFFALO-FISHES. 
(This genus contains an uncertain number of species, very few 
of which have been yet well defined. They are large, coarse 
suckers, especially characteristic of the streams of the Mississippi 
valley. The group much needs careful study, such as could only 
be given by a collector resident near some large market). (ix4vs, 
fish; Bots, buffalo.) 
a, Mouth large, terminal, protractile forwards; lips thin; lower pharyngeals 
and teeth weak. (Sclerognathus Cuv. & Val.) 
66. I. cyprinella (Cuv. & Val.). Common BuFrrato-Fisu. 
Rep-mMoutHED Burrato. Body robust, the outline somewhat 
elliptical; head very large and thick; opercle coarsely striate, 
nearly half length of head; lips scarcely plicate; color dull brown- 
ish olive, not silvery; fins dusky. Head 3}; depth 3. D. 28, A. 9; 
scales 7-37 to 41-6. L.3 feet. Miss. valley, etc., common; reaches 
20 to 40 pounds weight. (Lat., a small carp.) 
aa. Mouth smaller, more or less inferior, protractile downwards, and with 
thicker lips. 
b. Lower pharyngeal bones strong, the teeth comparatively coarse and 
large, increasing in size downwards; dusky species, not silvery. 
(Ictiobus.) 
67. I. urus (Agassiz). RAzor-BACKED BurraLo. MoNnGREL 
Burrato. Body not much elevated, the back not keeled, the 
axis of the body not much farther from back than from line of 
belly ; head thicker and blunter than in J. bubalus; eye smaller 
than in J. bubalus ; mouth much larger and more oblique, approach- 
ing that of I. cyprinedla, but with lips thicker and plicate, the folds 
broken up into papille ; longest dorsal rays scarcely half of base of 
fin, opercle coarsely striate. Color very dark; fins dark. Head 
34 to 4; depth 3. D. 30; scales 8-41-7. L. 2} feet. Miss. valley, 
less common than the others; certainly different from J. bubalus, 
but not always distinguishable by me from J, cyprinella, and possi- 
bly not really different. (Lat., a wild bull.) 
68. I. bubalus (Rafinesque). SucKER-MOUTHED BuFFALO. 
SmMaLL-MouTHED Burrao. Body considerably elevated, the 
back compressed; axis of body much nearer line of belly than 
back; head not very blunt, the mouth small and inferior ; eye 4 to 
5 in head, rather large ; longest dorsal rays much more than half 
base of fin in adult; coloration dusky, the fins scarcely black. 
Head 4; depth 22; D. 29; scales 8-39-6. L. 24 feet. Miss. valley, 
ete., common. (Bubalichthys bubalus Agassiz.) (Lat., buffalo.) 
