LEUCISCUS HECKELII. 183 



o£ eight to thirteen rays, which sh'ghtly festoon its free border. The lateral 

 line is more or less parallel to the ventral contour. The pharyngeal teeth 

 show in most eases the formula 6^5, though the formula 5 — 5 is occasionally 

 met with. 



The bouy is dark blue-grey, with metallic lustre, and the abdomen is 

 silvery. The upper sides of the body and head have innumerable black 

 flecks. A dark blue-grey band extends from the eye to the base of the tail, 

 but is distinct only in specimens in which the black spots are few in number. 

 It recalls the form of L. adsperstis of Dalmatia. 



It is abundant in the Guadiana, and less frequent in the Guadalquivir 

 at Seville. Its length is six inches. 



Leuciscus heckelii (Nordmann). 



D. 13, P. 17, V. 9, A. 12—13, C. 19. Scales: lat. line 43—46, trans. - 



d. 



This large species of Leuciscus has the height and form of a Bream, but is 

 more like the Rudd. Its length is usually from eleven to fourteen inches. 

 In a full-grown individual the height is one-third of the total length. The 

 head is scarcely one-sixth of the total leugth ; it is thick, and rather flattened 

 at the top. The snout is rounded and thick, and extends beyond the small 

 mouth, which in consequence has a somewhat inferior position. The eyes are 

 of medium size, and placed rather higher than in the Rudd. 



The scales are lai-ge, adherent, and harder than in the Rudd ; they usually 

 have from three to five rays. 



The dorsal fln is above the middle of the base of the ventral fin, and 

 consequently placed farther forward than in the Rudd. Its first branched 

 ray is somewhat longer than the head ; it is twice as high in front as behind, 

 and its terminal border is concave. The proportions of the anal fin are 

 similar. There are four and a half longitudinal series of scales between the 

 lateral line and ventral fin. 



The fish is entirely silver-white, with some bluish-grey on the head and 

 back, and pale yellow on the sides. The eyes are yellow, with silver and red 

 tints. The lower fins ai-e pale yellow, the dorsal fin is darker ; all are bordered 

 with black. 



This fish is known only from the Crimea. 



