668 



Frits Johansen. 



as also its lower and upper edge. Above a line from the horizontal 

 diameter of the eye a little above the base of the pectorals to the 

 lower base of the caudal fin the ground-colour is black-brown; 

 lower down it is silvery with black dots, which however nowhere 

 conceal the under-colour and are fewest from the base of the ventrals 

 to the anus. The ground-colour of the mouth is whitish-blue; this 

 and the throat have a dense collection of dark-gray dots at the 

 places where there are skeletal parts and a little round about; these 

 dots of pigment are also present on the gill-arches, especially on 

 their upper side, less on the silvery lower side. The inner side of 

 the gill-cover silvery-golden (the latter especially on the upper part) 

 with black dots; the gills pale-red-lilac. All the fins are blackish- 

 brown; the pectoral and anal fins have the colour of the belly at 

 their base (though more whitish-blue than silvery), farther out the 

 colour changes to blackish-brown. The peritoneum silvery with 

 black pigment. 



Salmo alpinus L. 



This species is very common in every large lake (that is, which 

 does not dry up in summer). That the fish may also live, however, 

 in lakes with salt bottom-water is shown by its capture in Sælsøen ^ 

 and in the outlet to this (the large river) behind Hvalrosodden. 

 This place is also the only one, where a migration from the lake 

 to the sea (July) and from the latter to the lake (September) has 

 been observed with certainty; many of the other lakes in which 

 the fish was found, probably have too small an outlet to allow it 

 to pass through or return again, before the outlet dries up or be- 

 comes frozen over. A few smaller fish were seen however in the 

 harbour in July 1907 and one taken up in the lake above the same 

 place almost at the same time contained in its stomach one of the 

 common, marine-littoral Amphipods, which shows that it must have 

 been out in the salt water. 



In winter the fish is seen under the ice, where it does not go 

 down to the bottom (harbour, September— October 1906); they are 

 very active and the large especially are very greedy (capture of a c? 

 of 416 mm on 22.— 9.— 06 on lines); it is not until June however 

 that sufficient ice is melted near the shore and the fish seen there 

 in the open water (Gaasesøen 1907 and harbour 1908). 



In the summers of 1906, 1907 and 1908 I had excellent oppor- 

 tunities of observing the migration of this fish from the lake to the 

 sea and back again, namely at Sælsøen behind Hvalrosodden. At 



' Regarding the natural conditions of this lake see my paper: "Freshwater 

 Life etc.". Medd. cm Grönland, XLV. 



