GEN. LEUCISCUS. THE DOUBLE ROACH. 69 



and anal fins are short, and there are no spines or 

 barbules. It constitutes a group containing numer- 

 ous- species, which are distinguished by the position 

 of the dorsal fin. They are valued not so much for 

 food as for bait. In the first sub-genus this fin is 

 immediately above the ventrals. 



(Sp. 105.) L. dohula. The Double Roach. This 

 is the first species named in the Regne Animal, 

 and is described as having a rounded muzzle, with 

 red pectoral and ventral fins. According to Bloch, 

 it rarely exceeds half a pound in weight, and feeds 

 upon worms and aquatic mollusca ; it prefers clear 

 rivers and large lakes, and spawns in March and 

 April. It is known to inhabit the Oder, Elbe, 

 Weser, Rhine, and their tributaries. Its flesh is 

 white, but full of bones, and it is little esteemed for 

 the table. It was first catalogued as a British fish 

 by Mr. Yarrell, who, while fishing in August 1831, 

 ii> the Thames, below Woolwich, with the mouth 

 of a white-bait net open against a strong flood tide, 

 caught a single specimen; and no other has been 

 since observed. Mr. Yarrell's specimen was six 

 inches and a half long ; the upper parts of its body 

 were dusky blue, becoming brighter on the sides, 

 and passing into silvery white on the belly; the 

 dorsal and caudal fins were dusky brown, the pec- 

 toral, ventral, and anal, pale orange ; irides orange ; 

 cheeks and opercle, silvery white. 



(Sp. 106.) Z/. idus. The Ide. The claims of 

 this species to be considered as British are very 

 limited ; but we insert it, after the examole of Mr. 



