S24 LAKE TROUT. 



in the lower javr, and witliin on each side near the front a short 

 separate row. Tongue fleshy, with a double row of not very- 

 large teeth. Being a male there was the kipper or turned-up 

 process on the front of the lower jaw, but not so high as in 

 the Salmon; and it was received into a cavity in the upper 

 jaw. Nostrils above the level of the line from eye to snout; 

 scales on the body round, those along the lateral line shining; 

 origin of the dorsal fin one foot and an inch from the snout; 

 adipose fin large, and not far from the tail; its upper part 

 widest. Width of the tail eight inches, and at its root three 

 inches and a fourth; the border might be called straight, except 

 that there is a small point at the corner above and below; 

 pectorals rather wide, the upper rays curved. The colour along 

 the back and upper part of the sides dark, tinted with blue, 

 as are also the dorsal fin and tail; cheeks yellow, covered, as 

 is the body, very thickly with round dots; none on the belly; 

 pectorals and ventrals yellowish; anal dark. A tinge of purple 

 on the sides, where the scales shine as if pearly. The dark 

 spots on the body are also spread over the dorsal fin and tail; 

 and even on the lower portion of the transparent cornea (of 

 the eye.) 



In an example from Malham Tarn of much less size, the 



muscular structure appeared more decided; the tail broader and 



more round; dorsal and anal fins more developed; a more 



decided tinge of yellow along the sides; the adipose fin reddish; 



and the spots proportionally larger, with a warm tinge. 



In a comparison of several examples, Mr. Thompson found 

 permanent differences between the sexes; the teeth being con- 

 siderably stronger in the male; the distance from eye to snout 

 greater; and the form of the operculum is different, that of tlie 

 female approaching in roundness to that of the Salmon. In 

 some instances the spots in the male have a pale circle of dull 

 orange round them. 



I found the fin rays of the dorsal to be twelve, anal ten, 

 pectoral thirteen, caudal twenty. 



