144 THE FRESH- WATER FISHES OF EUROPE. 



and the lateral band of a lead-blue tint, so characteristic of Leuciscus aula, is 

 either wanting or only partially developed. Its length is from two to six 

 inches. It is not known north of the Tyrol, but is found in Lake Garda and 

 other Italian localities, in Istria and Dalmatia, and at Brusa, in Asia Minor. 



Many authors, like Canestrini, Giinther, and Fatio, refuse to recognise 

 it even as a variety, because intermediate forms can be found, and individuals 

 of the species Leuciscus aula present characters found in this fish ; but such 

 a proceeding prejudges the question of specific variation, and it seems to us 

 more convenient to recognise the variety as exhibiting a direction in which the 

 species Leuciscus aula tends to become modified. Von Siebold would go so far 

 as to regard the fishes which have been referred to Leuciscus rubella, L. aula, 

 L. adspersus, and L. basak, as varieties of Leuciscus rutilus. 



HeckePs second variety, L. basak, is found only in Dalmatia, where it is 

 locally known under the name Basak, and occurs in the Lago di Drusino, near 

 Imosky, and in other localities (See FRONTISPIECE). 



It is remarkable for the small size of the forehead, and has small scales on the 

 back. Moreover, the body is so attenuated that its height is only equal to the 

 length of the head, and the head is nearly one-quarter of the length of the fish. 

 Hence the head is relatively larger than in L. rubella. The eye is large, being 

 one-quarter of the length of the head, and is removed from the rather pointed 

 snout by its own diameter. The dorsal fin is higher than in the previously 

 described variety, and has a shorter base. There is no trace of the longitudinal 

 lateral band. 



LeuciscTis adspersns (HECKEL). 



above 15 16 



D. 10, A. 10, V. 9, P. 14, C. 19. Scales : lat. line 5860 



below 6 7. 



This is another of the fishes of Dalmatia described from a small lake near 

 Imosky, which is deeply sunk, like a crater, among the surrounding rocks. 

 The lake is known as the Jessero rosso, and has a subterranean outlet, in which 

 the fish also occurs. The species is locally known as the Gaovize (Fig. 72). 



In aspect it somewhat resembles the Minnow. 



The length of the head is equal to the height of the body ; the scales are 

 small ; and the entire body is spotted with blackish-brown pigment. There 

 is on each side a single row of pharyngeal teeth. As in the variety basak, of 

 the preceding species, the head is one-quarter of the length of the body, and 

 the eye one-quarter of the length of the head, similarly distant from the 

 snout, and also one and a half times its own diameter from the other eye. 



