168 Bulletin 47, United States National Museum. 



269. CARPIODES CYPRINUS, (Le Sueur). 



(EASTERN CARP SUCKER.) 



Very similar to C. velifer, the mouth similar but the opercle nearly 

 smooth with scarcely any wrinkles or furrows. Body rather elongate. 

 Eye quite small; dorsal fin high, color silvery, dorsal dusky; paired fins 

 edged with white. Streams about Chesapeake Bay, common in the Chesa- 

 peake and Potomac, rare in the Delaware, (cyprlnus, carp.) 



Catostomm cyprinus, LE SUEUR, Jour. Ac. Nat. Sci. Phila., i, 1817. 91, Elk River and other 



tributaries of Chesapeake Bay; GUNTHER, Cat., vn, 19, 18G8. 

 Carpiodes vacca, AGASSIZ, Am. Jour. Sci. Arts, 1854, 256, Susquehanna River. 



90. CYCLEPTUS, Rafinesque. 

 (BLACK HORSE.) 



Cydepius, RAFINESQXTE, Jour. Phys. Chymie. Hist. Nat. Paris, 1819, 421, (nigrescent). 

 Rhytidostomus, HECKEL, Russeggers Reisen Syrien, 1023, 1842, (elongatm). 



Head very small, short and slender, 6 to 7 times in body ; its upper 

 surface rounded. Eye small, behind middle of head, not very high up. 

 Suborbital bones small and narrow. Fontanelle entirely obliterated by 

 the union of the parietal bones. Mouth small, entirely inferior, overlapped 

 by the projecting snout; upper lip thick, pendent, covered with several 

 rows of tubercles ; lower lip moderate, formed somewhat as in Catostomus, 

 but less full, incised behind. Jaws with rudimentary cartilaginous sheath. 

 Muciferous system not greatly developed. Operculum smooth and narrow. 

 Isthmus moderate. Gill rakers moderate, soft. Pharyngeal bones strong ; 

 the teeth stout, increasing in size downward, rather wide apart. Body 

 elongate, moderately compressed, not much elevated ; the caudal peduncle 

 long ; scales moderate, about equal over the body, with wide, exposed 

 surfaces, the number in the lateral line from 55 to 60. Lateral line well 

 developed, nearly straight. Fins rather large; dorsal fin beginning in 

 front of ventrals and ending just before anal, of about 30 rays, strongly 

 falcate in front, the first and second developed rays in length more than 

 i length of base of fin, the rays rapidly shortened to about the eighth, 

 the remaining rays being all short ; caudal fin large, widely forked, the 

 lobes about equal. Anal fin quite small, low, of 7 or 8 developed rays, 

 scaly at base. Ventrals moderate, with 30 rays. Pectorals elongate, 

 somewhat falcate. Sexual peculiarities marked ; the males in spring 

 with black pigment ; the head then covered with small tubercles. Air 

 bladder with 2 chambers, the anterior short, the posterior elongate. 

 One species known. (KVKAO? , round ; Aenrof , slender ; "the name means 

 small round mouth." Eafinesque.) 



270. CYCLEPTUS ELONGATTJS, (Le Sueur). 



(BLACK HORSE ; GOURD-SEED SUCKER ; MISSOURI SUCKER ; SUCKEREL.) 



Depth 4 to 5 in length ; head 6 to 8i ; eye small, 6 to 7 in head. Dorsal 

 rays 30; anal 7 or 8; scales 9-56-7. Longest dorsal rays a little longer 

 than head; pectorals rather longer than head. Coloration very dark, 



