CATOSTOMID. — XXV. 45 
bb. Lower pharyngeal bones narrow, with the teeth thin and weak; species 
* of pale coloration, more or less silvery. (Carp Suckers.) (Carpiodes 
Rafinesque.) 
c. Body subfusiform, the depth about 3 in length, lips thin, silvery white in 
life, the halves of the lower lip meeting at a wide angle. 
69. I. carpio (Rafinesque). Back compressed, little arched ; 
snout not blunt, projecting little beyond the mouth, its length a 
little more than that of eye; nostrils not close to tip of snout ; 
opercle strongly striate ; longest dorsal rays 2 to 2 length of base 
of fin, the anterior rays sometimes thickened, never filamentous ; 
eye small, 44 to5 in head. Head short, 4 in length; depth 3. D. 
25 to 27; scales 7-37-5. Color dull silvery, sometimes brassy, some 
of the scales above often brownish at base. Ohio valley to Texas ; 
probably a valid species, but of doubtful name and synonymy. 
(Lat., carp.) 
cc. Body ovate-oblong, the back elevated, the depth about 2} in the length. 
d. Opercle strongly striate. 
e. Lips thin, silver-white in life, the halves of lower lip meeting at a 
wide angle, as in J. carpio. 
70. I. difformis (Cope). Similar to J. velifer, but with very 
blunt snout, the maxillary reaching front of pupil ; nostril very 
near tip of snout and above or before upper lip; eyes large (385 to 
4 in head); dorsal very high. Head 4; depth 23. Ohio valley. 
71. I. thompsoni (Agassiz). Resembles J. velifer, but with 
the head small and pointed, the snout considerably projecting ; 
eye small, 5 to 54 in head. Back arched. Head 41; depth 25. 
Great Lakes, abundant (specimens examined from Toledo). (For 
Rev. Zadock Thompson.) 
ee. Lips full, thick, flesh-colored in life, the halves of lower lip meeting 
at an acute angle. 
72. I. velifer (Rafinesque). QUILL-BACK. SKIM-BACK. CARP 
Sucker. River Carp. Snout sub-conic, projecting; anterior 
nostril distant from snout more than half an eye’s diameter and 
considerably behind front of upper lip ; maxillary reaching about 
to front of orbit; eye moderate or small, 4 to 5 in head; ante- 
rior rays of dorsal always elevated and filamentous, infrequently 
as long as base of fin. Head 32 to 44; depth 2} to 3. D. 26; 
scales 7-37-5. Coloration usually pale. Miss. valley, etc., very 
abundant; variable. (Lat., bearing sails.) 
dd. Opercle nearly smooth. 
73. I. cyprinus (Le Sueur). Carp Sucker. Body rather 
deep, the eye quite small, the dorsal fin high, otherwise essentially 
as in J. velifer. Pa. to Va., chiefly about Chesapeake Bay. (Lat., 
carp.) 
