288 THE FRESH-WATER FISHES OF EUROPE. 



become paler, and the black spots of the back and head become a deeper black, 

 and their round form alters to an irregular X-shape. All the fins, except the 

 dorsal, show traces of coloured spots, and are edged with blackish-blue. This 

 species does not migrate. 



Salmo microlepis (GUNTHER). 



on 



D. 1314, A. 11, P. 14, V. 9. Scales : lat. line 135140, trans. - 



30. 



The Trout thus named is known only from specimens, a little over eight 

 inches long, from Hungary. The body is greenish or brown, with a silvery lustre, 

 and round or reticulate black spots on the side, among which red or orange 

 spots are more or less plentifully scattered. 



One of the specimens has twelve transverse Parr marks. The fins are free 

 from black or yellow colour on the margin. There are fifteen or sixteen 

 scales in an oblique series, descending backward from the adipose fin to the 

 lateral line. The head is short, and the body slender. The snout is short, and 

 the broad maxillary bone does not extend to the hinder margin of the eye. The 

 teeth on the vomer are in a zigzag line, and, therefore, presumably in a double 

 row. The pectoral fin is not pointed. The caudal is emarginate. There are 

 sixty to sixty-one vertebrae, and seventy-two pyloric appendages. 



This fish differs from the Salmo lacnstris, in having three extra rows of 

 scales above the lateral line ; and in the absence of mature specimens, we must 

 regard the large number of scales in the lateral line as marking an interesting 

 specific variation from that type. 



Salmo fario (LINN^US). The Biver Trout. 



D. 1314, A. 1112, P. 14, V. 9. Scales : lat. line 120, transverse 2730. 



There are two principal forms of the River Trout. One is characteristic 

 of Scandinavia, Iceland, Scotland, and Ireland, and the other occurs through- 

 out Central Europe, Russia, South Britain, and ranges into Sweden. The 

 former variety is distinguished by Dr. Giinther as S. gaimardii, this name 

 having been given by Cuvier and Valenciennes to the Trout from Iceland, 

 figured by Monsieur Gaimard. The second variety is named S. ausonii, a 

 name given by Cuvier and Valenciennes to a French example of the species. 

 Both varieties occur in Britain, the southern forms ranging as far north as 

 the Rivers Eden and Calder, and the northern form, according to Giinther, 

 extending as far south as Shropshire. For this latter we are disposed to reserve 

 the name Salmo fario, as it certainly was the fish known to Linnaeus. 



