1. SALMO. 135 



third half as long as the fourth, the fourth simjjle, five-sixths of the 

 fifth, which is branched, the sixth the longest, the last split to the 

 base. The length of the base of the dorsal is contained once and 

 one-third in its distance from the adipose fin. 



The origin of the anal fin is exactly in the middle between the 

 root of the caudal and that of the outer ventral ray ; the length of 

 its base is less than that of the dorsal, and not much less than its 

 height. The four anterior rays are enveloped in a common mem- 

 brane ; the fourth and fifth rays form a rounded point ; and the lower 

 edge of the fin is slightly emarginate. The first ray is short, the 

 second half as long as the third, the third three-fourths of the fom-th, 

 the fourth simple, a little shorter than the fifth, which is the longest 

 and branched ; the last split to the base, its length being nearly one- 

 half of that of the fifth. 



Caudal fin emarginate, the length of a middle ray being a little 

 more than one-half of that of the outer ones, the length of which is 

 contained six times and a half in the total. Lobes slightly rounded. 



The base of the pectoral is overlapped by the gill-cover apparatus. 

 It extends nearly to the vortical from the origin of the dorsal, is 

 considerably shorter than the head, its length equalling three-fourths 

 of the distance between its root and that of the ventral. 



The ventral is inserted in the vertical below the eighth to the 

 eleventh dorsal rays, its length being two-thirds of that of the pectoral, 

 or of the distance between the root of its outer ray and the vent. 



The scales are very thin and small, deeply imbedded in the skin ; 

 one taken from between the dorsal and the lateral line is ovate, two- 

 thirds as high as long. The perforated scales of the lateral line do 

 not correspond to the transverse series. Scales on the back minute. 



The back is dark sea-green, which colour becomes lighter on the 

 sides, assuming a yellowish shade and gradually passing into the 

 bright red of the lower parts ; sides with numerous reddish orange- 

 coloured dots. Pectoral greenish, passing into reddish })osteriorly, 

 the upper margin being white ; ventral and anal red, with white 

 anterior margins ; dorsal and caudal blackish, with broud lighter 

 margins. Cheeks and suboperculum \vith numerous black dots. 



8. Salmo rutilus. 



Ascan. Ic. tab. 32. 



Salmo rutilus, Nilss. Prodr. p. 10, and Skand. Faun. Fisk. p. 430. 



ascanii, Cuo. ^ Val. xxi. p. 25G. 



Of this fish scarcely more than the name is luiown ; Nilsson has 

 characterized it thus : — 



Yellowish, brownish above, red or orange-coloured below, sides 

 with small light spots. Head small, its length being contained five 

 times and one-third in the total. Snout pointed, with the lower jaw 

 sometimes prominent. Ventrals and anal red, with the anterior 

 margins white. 



Lakes of South-western Norway (Hadeland ; neighbourhood of the 

 coast in Christiansands stift). 



