270 OYPRINID-E. 



which is not wider than the preceding bono. The origin of the 

 dorsal fin is behind the root of the vcntrals, and more distant from 

 the end of the snout than from the root of the caudal. Caudal fin 

 moderately forked. The pectoral fins terminate at a considerable 

 distance from the ventrals. Scales much higher than long on the 

 side of the body. There are seven longitudinal series of scales 

 between the lateral line and ventral fin. Humeral region blackish. 

 A black spot on the base of the anterior dorsal rays ; a dark longi- 

 tudinal lateral band, terminating in a blackish spot at the base of 

 the caudal fin, is more distinct in immatui-e than in adult examples. 



Pharyngeal teeth 4 . 2 — 2 . 4 or 5, but slightly compressed, termi- 

 nating in a hook. GiU-rakers veiy short and few in nimibcr. The 

 attachment of the giU-membranes to the isthmus takes place some- 

 what in advance of the angle of the prfeoperculum. 



United States. 

 a-d. Adult and half-grown. Susquehannah River. Purchased of 



0. Salvin, Esq. 

 e. Adult. Tioga CO., Xew York. Presented by Th. Moore, Esq. 

 f-li. Adult skins. Lake Erie. Purchased of Mr. ParneU. 

 V. Adult skin. Ohio Canal. Purchased of Mr. Parnell. 



B. Somn of the pharyngeal teeth are obtuse and molar-like. 



7. Leucosomus canrinus. 



Cyprinus (Leuciscus) caurinus, Jtichards. Faun. Boreali-Amer. Pise. 



p. .304. 

 Mylocheilus lateralis, Agass. 8f Pick. Sillim. Journ. 1855, xix. p. 2-31 ; 



Girard, in U. S. 8r Pac. R. R. Exped. Fish. p. 214, pi. 48. figs. 5-8. 

 Mylocheilus caurinus, Girard, in U. S. S,- Pac. R. R. Exped. Fish. p. 213, 



pi. 40. figs. 1-4. 

 fraterculus, Girard, I. c. p. 215, pi. 45. figs. 1-4. 



D. 10. A. 10. V. 10. L. lat. 74. L. transv. 15/13. 



Head and body rather low and elongate ; the height of the body 

 is contained five times in the total length (without caudal), the 

 length of the head four times and one-fourth. The width of the 

 interorbital space (which is slightly convex) is equal to the length 

 of the snout. Eye of moderate size, its diameter being one-half of 

 the length of the snout, and one-third of that of the postorbital 

 part of the head. Mouth horizontal, of moderate width, the maxil- 

 lary not extending to the vertical from the front margin of the eye. 

 Upper jaw overlapping the lower. Lips well developed. Suborbital 

 bones narrow, the prseorbital being longer than the eye and more 

 than twice as large as the postorbital. The origin of the dorsal 

 fin is nearly opposite to that of the ventral fin, and nearly midway 

 between the end of the snout and the base of the caudal. Caudal 

 fin forked. There are eight longitudinal series of scales between 

 the lateral line and ventral fin. A narrow dark band (more or less 

 conspicuous) runs along the middle of the side of the body. 



Pharyngeal teeth 5 . 2 — 2 . 5, the lower stout, obtusely rounded 

 at the top, molar-like ; the two upper compressed, terminating in a 



