330 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [8] 



are trout, at which I was astonished, as the mountain-trout is much 

 more inclined to seek the bottom, because it draws the food toward 

 itself, while the trout snatches the food when swimming rapidly. The 

 entire northern portion of the lake is important on account of the num- 

 berless ducks found here, so that the profit gained from the sale of eggs 

 far exceeds that obtained from the fisheries. 



Besides the cold streams which flow into Lake Myvatn from the lava 

 fields, there are some streams whose temperature is always higher than 

 that of the air. The warm dam near Yogar had a temperature of ID^o 

 Celsius at 1 p. m. on July 28. At the same time the temperature of the 

 water of the lake in the immediate vicinity of this dam was 15° Celsius, 

 both at the surfiice and at the bottom, while the temperature of the at- 

 mosphei-e was also 15°. It is evident tliat such favorable conditions 

 of temperature must exercise a considerable influence on the plant and 

 animal life. 



At the farm of Mr. Haldur, at Kalfastrand ,1 had an excellent oppor- 

 tunity to examine thoroughly the character of the fish of Lake iMyvatn. 

 Mr. Haldur is one of the most expert and best-informed fishermen on 

 Lake Myvatn, and his information seems to be reliable. Near Kalfa- 

 strand the mountain-tront spawn after September 20, and it is supposed 

 that this early spawning season is caused by the numerous springs in 

 this southern part of Lake Myvatn. At Geiteyarstrand the spawning- 

 season begins somewhat later. In December it comes to a close, but 

 occasionally specimens of mountain-tront, ready to spawn, have been 

 caught in the latter half of April. I examined some of the several or- 

 gans of the fish which we caught, i^either spawn nor milt seemed 

 sufficiently developed to warrant as early a commencement of the 

 spawning season as the end of September. The eggs were not larger 

 than grains of mustard, and Mr. Haldur informed me that they reached 

 the size of peas. 



On the southern shore of Lake Myvatn I heard i)eopIe talk a good deal 

 about a little fish which they called krus. After many vain endeavors I 

 succeeded in obtaining a piece of this fish. It is nothing but a variety 

 of mountain-trout, but it is remarkably dark, and its head and body 

 appear to be heavier than those of the mountain-trout. It is said to 

 live in the fissures, crevices, and holes of the lava, and it is supposed 

 that many of the subterranean lakes in the interior of the island are 

 connected with Lake Myvatn. It may be that the variety of the mount- 

 ain-trout which the natives called Irus is influenced by the stay in these 

 subterranean waters, and that from this circumstance it derives its dark 

 color. The opinion that there is some sort of connection between the 

 various subterranean waters of Iceland is widely spread, and on Lake 

 Myvatn I was shown a ring which had been lost in the lake, and was 

 found in a trout caught in a little lake near Husavik. 



The fisheries on Lake Myvatn are carried on with floating-nets and 

 stationary nets. These are 10 or 12 fathoms long and 2 feet deep (four 



