128 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
6. Ameiurus nlveiventris (Cope). L. N. “ Fork-tailed Cat.” 
Only young specimens. The body seems slenderer, the caudal more deeply forked 
than in the young of A. albidus. A. 21 to 23. Color silvery, the fins darker. 
7. Catostomus nigricans (Le Sueur). N, 
Common. 
8. Erimyzon sucetta (Lac^pfede). M.,L.,N. 
Very common; scales 46. 
9. Moxostoma papillosum (Cope). L.,N. 
Very common. Snout projecting beyond the very small mouth ; head short and 
broad, with large eye. D. 14, the edge of the fin straightish ; caudal lobes equal. 
Pharyngeal bones weak. 
10. Moxostoma conus (Cope). L. 
A single young specimen. Head very short and small, the short, narrow snout 
projecting beyond the small mouth ; lips full, the i)OSterior truncate. D. 12, the fin 
high, its free border concave, the first rays being much produced. Caudal deeply 
forked, the upper lobe a little longer. This species is very closely related to the species 
found in the Ohio River and Lake Erie, which is apparently Moxostoma breviceps^ (Cope). 
11. Moxostoma crassilabre (Cope). L. 
One large specimen. Body robust, the back elevated ; head short, broad, fiattish 
above; mouth moderate, the lips full, the lower truncate behind ; snout short, little 
projecting beyond mouth. Head 5 in length ; depths^. D. 13. Caudal lobes equal; 
dorsal with its free edge much incised, the anterior lobe about as long as head. 
Pharyngeals weak. Color rather dusky ; many of the scales with a dusky shade at 
base; top of head, humeral bar, and especially a broad shade across dorsal fin, black- 
ish. Some red on anal and caudal fins. 
Compared with Moxostoma hreviceps from Cincinnati, this species is much more 
robust, with larger, broader, and much more flattened head. The eye is larger, the 
snout much shorter, and the preorbital is much broader. This bone is quite narrow 
in M. breviceps. In 31. breviceps the top of the head is very convex transversely, the 
dorsal lobe is 1:^ times length of head, and the upper lobe of the caudal is much 
prolonged. 
The resemblance of 31. crassilabre to M. aureolum from Toledo is much greater, 
the only prominent difference being that M. aureolum has the upper outline of the 
dorsal slightly convex. 
M. macrolepidotum (the true eastern form, as distinguished from the western, 
M. duquesnei).! from Potomac River, is also very close to M. crassilabre. The two have 
the same general form and coloration and the same form of the mouth and of the 
dorsal fin. In comparing a single specimen of each, I find that crassilabre has a still 
shorter and blunter head and higher back. The eye in crassilabre is IJ in snout, the 
head 5 in body. In macrolepidotum the eye is If in snout, the head 4f in bodj". It is 
probable that M. crassilabre will prove to be a slight variety of 31. macrolepidotum. 
31. duquesnei, the western red-horse, may differ in the slightly longer head, and in not 
'This species is described in the fifth edition of Jordan’s Manual of the Vertebrates as Moxostoma 
crassilabre (Cope), which is, however, a different species. 
