133 



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 Roach L. pigus L. friesii The Chub The Dace L. illyricus 

 L. pictus L. svallize L. ukliva L. turskyi L. microlepis L. tencllus L. muticellus 

 the Minnow L. hispanicus L. arcasii L. alburnoides -L. macrolepidotus L. arrigonis 

 L. lemmingii L. heckelii L. pyrenaicus L. polylepis GENUS PAHAPHOXINUS GENUS 

 , TINCA : The Teach GENUS CHONUHOSTOMA : C. nasus C. phoxinus C. genei C. knerii 

 C. rysela C. polylepis C. willkommii. 



GROUP: LEUCISCINA. 

 GENUS: LeUCiSCUS (CuviER). 



LEUCISCUS is one of the most important genera of Cypriuoid fishes. Dr. 

 Giinther groups with it, in an assemblage termed Leuciscina, the genera Cteno- 

 pharyngodon of China, Mylopharodon of California, Paraphoxinus of Dalmatia, 

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

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

 the Columbia River. Its European allies all belong to genera poorly 

 represented in species ; 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 understood by Cuvier and by Giinther, has the 

 body covered with imbricated scales ; tha 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 anal fin generally has from nine to eleven rays, and 

 is rather short. The pharyngeal 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 Pseudopkoxinus. 

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

 divided, so that the name Phoxinus has been used for those which have the 



