358 THE FRESH-WATER FISHES OF EUROPE. 



Thymallus microlepis (STEINDACHNER). 



above 1922 

 D. 1314, A. 12. Scales: lateral line 110 



below 1719 



The body is elongated, and the tail compressed, so as to form a sort of 

 edge, which disappears on the fore-part of the back. The height of the body 

 slightly exceeds the length of the head. 



The height of the head is two-thirds of its length. The snout is some- 

 what truncate, and projects a little over the mouth. The cleft of the mouth 

 is short, and its angles are below the middle of the eye. There is a row of 

 small pointed teeth in the pre-maxillary and maxillary bones, and in the man- 

 dible. The lateral rows of teeth on the tongue are much larger. There are 

 two long rows of vomerine teeth. The eye varies from a quarter to less than 

 a fifth the length of the head. The frontal region of the head is nearly flat. 

 There are eleven branchiostegal rays. The gill-aperture is wide. The hinder 

 border of the operculum is very little curved. The lower border of the pre- 

 operculum is more rounded. 



The dorsal profile rises in a moderate arch to the dorsal fin ; the ventral 

 contour is flatter. The dorsal fin is in advance of the middle of the body. The 

 insertion of the ventral fin is in the middle of the length, and below the 

 hinder part of the dorsal. The dorsal fin is as high as its base is long, and 

 about half as long again as the head. The anal fin is two-thirds the length of 

 the dorsal. Both these fins have their posterior free margins slightly concave. 

 They are most elevated at the fifth ray, which is jointed and branched. The 

 caudal fin is forked, with pointed lobes, which are only a little shorter than the 

 length of the head; its base is covered with scales. The pectoral fin, which 

 has fourteen rays, is longer than the ventral, but shorter than the head. The 

 ventral fin contains ten rays ; over its base is a rather long spur-like scale, 

 which is covered with smaller scales in its front part. The adipose fin is above 

 the hinder half of the anal. 



The scales are smaller than in the Common Thymallus, but quite as firm in 

 texture, and more nearly uniform in size. The body is completely covered 

 with scales, without any of the naked patches which characterise the Grayling. 

 The smallest scales are on the throat, and increase in size towards the ventral 

 fin. The largest scales are above and below the lateral line. 



The lateral line is nearly straight. It includes one hundred and ten perfo- 

 rated scales, of which from four to eight are upon the base of the caudal fin. 



