1:^8 



CHAPTER V. 



FRESH -WATER FISHES OF THE ORDER PHYSOSTOMI {continued). 



GROUP LEUCISCINA— Genus Leuciscus : The Rudd, and its Varieties— The Ide—Leuciscus 

 aula — L. adspersus — The Eoach — L. pigus— L. friesii — The Chub — The Dace — L. illyricus — 

 L. pictus — L. svallize— L. ukliva — L. turskyi — L, microlepis — L. tenellus— L. muticellus — 

 the Minnow — L. hispanicus — L. arcasii — L.. alburnoides — L. iriacrolepidotus — L. arrigonis — 

 L. lemmingii — L. heckelii — L. pyrenaicus — L. polylepis — Genvs PAstAPHoxiNus — Genis 

 Tinca: The Tench — Gexus Chonbhostoma : C. nasus— C. phoxiaus — G. genei — C. knerii — 

 C. rysela — C. polylepis — C. willkommii. 



Group: LEUCISCINA. 



Genus: LeUCiSCUS (Cuvier). 



Leuciscus is one of the most important g-enera of Cypriuoid tislies. Dr. 

 Gliiitlier groups with it, in an assemblage termed Leucisciua, the genera Cteno- 

 pharpigodon of China, Mt/lopharodon of California, Parajohoximis of Dalmatia, 

 Meda of South America, Tinea, Leucosomus of North America, Chondrostuma 

 of Europe and Western Asia, Orthodon of California, and AcroeJiilns of 

 the Columbia River. Its Eui'opean allies all belong to genera poorly 

 represented in sj^ecies ; but Dr. Giinther enumerates in his catalogue no 

 fewer than thirty-five species of Leuciscus in the Old World, and forty-nine 

 species in America. These species, however, have been divided by modern 

 naturalists into a multitude of genera, founded on characters which have 

 little value. The genus, as umlerstood by Cuvier and by Giinther, has the 

 body covered with imbricated scales ; the lateral line runs along the middle 

 line of the tail, or a little below it ; the dorsal fin is almost always opposite 

 to the ventrals ; the aual fin generally has from nine to eleven rays, and 

 is rather short. The jiharyng-eal teeth may be conical or compressed; the 

 intestine is short, with few convolutions. 



The Old World species admit of being subdivided by the characters 

 of the pharyngeal teeth, lateral line, and dorsal and anal -fins. First, 

 there are the species with the pharyngeal teeth in a single series ; and 

 some Continental writers limit the genus Leuciscus to such species of this 

 type as have at least ten rays in the anal fin, and have the dorsal fin 

 opposite to the ventrals ; but when the anal fin has but nine rays, and the 

 dorsal fin is behind the ventrals, they name the type Psejidojokoxinus. 

 Secondly, the species with the pharyngeal teeth in a double row are sub- 

 divided, so that the name Plio.i'iiins has been used for those which have the 



