56. LEuciscus. 20/ 



Eighth Group. LEUCISCINA. 



Anal fin short or of moderate length, with from (seven) eight 

 to eleven branched rays, not extending forwards to below the 

 dorsal. Dorsal fin short, without osseous ray. Lateral line, if 

 complete, running along, or nearly in, the middle of the tail. 

 Mouth generally without barbels. Pharyngeal teeth in a single 

 or double series. 



56. LEUCISCUS. 

 Generic names employed for Old- World species. 

 Leuciscus, sp., Klein, Cuvier, Cuv. 4'" V(d. 

 Leuciscus et Plioxinus, Agassiz. 



Leuciscus, Scardinius, Squalius et Telestes, Bonaparte. 

 Idus, Scardinius, Leucos, Leuciscus, Squalius, Telestes, Plioxinus et 



Plioxinellus, Heckel. 

 Pseudoplioxinus &c.. Sleeker. 



Genenc names employed for New- World species. 

 Hypsolepis, (Baird) Sforer, Mem. Am. Acad. v. 1855, p. 284. 

 Hybopsis, Agassiz, Sillim. Journ. 1854, xvii. p. 358. 

 Ptycliocheilus, Agassiz, I. c. 1855, xix. p. 227. 

 AllDurnus, sp., Agassiz. 

 Alburnops, Codoma, Plarp:^^•us, Cyprinella, Moniana, Gila, Tigoma, 



Cheonda, Siboma, Ptychocheilus, Iludsonius, Hybopsis, Clinosto- 



mu8, Algoma, Algansea, Lavinia, Girard, Proc. Ac. Nat. Sc. Philad. 



1856, pp. 180-212. 

 Photogenis, Alburnellus, Phoxinus, Chrosomus, &c., Cope, Journ. Ac. 



Nat. Sc. Philad. xiii. 



Body covered with imbricate scales ; lateral line generally com- 

 plete, running in, or only a little below, the median line of the tail. 

 Dorsal fin short, without stiff ray, commencing opposite, rarely be- 

 hind, the ventrals. Anal fin rather short or moderately developed, 

 generally with from nine to eleven rays, rarely with eight (in small 

 species only), and still more rarely with fourteen rays. Mouth 

 without structural peculiarities ; lower jaw not trenchant ; barbels 

 none. Pscudobranchiae. Pharyngeal teeth conical or compressed, 

 in a single or double series. Intestinal tract short, with only a 

 few convolutions. 



Pala;- and Nearctic regions. 



The characters used for the distinction of subgeneric groups are 

 of so subordinate a value that no one would think of founding a 

 genus on them, but for the circumstance that it is desirable to 

 arrange the numerous species in a conspicuous manner. However, 

 as this can be done in a more simple way than by overburdening 

 the system with a number of names, which generally tend rather to 

 disturb the unity of the system than to indicate natural affinities, 

 I consider it best to drop them. A proceeding by which the Dace, 



