In Alaska the Dolly Varden, locally known as salmon-trout, is very destructive to the eggs of the salmon, and countless numbers are taken in the salmon-nets of Alaska and thrown away as useless by the canners. In every coastwise stream of Alaska the water fairly "boils" with these trout. They are, however, not found in the Yukon. In northern Japan occurs _Salvelinus pluvius_, the iwana, a species very similar to the Dolly Varden, but not so large or so brightly colored. In the Kurile region and Kamchatka is another large charr, _Salvelinus kundscha_, with the spots large and cream-color instead of crimson. [Illustration: FIG. 78.—Great Lake Trout, _Cristivomer namaycush_ (Walbaum). Lake Michigan. ] =Cristivomer, the Great Lake Trout.=—Allied to the true charrs, but now placed by us in a different genus, _Cristivomer_, is the Great Lake trout, otherwise known as Mackinaw trout, longe, or togue (_Cristivomer namaycush_). Technically this fish differs from the true charrs in having on its vomer a raised crest behind the chevron and free from the shaft. This crest is armed with strong teeth. There are also large hooked teeth on the hyoid bone, and the teeth generally are proportionately stronger than in most of the other species. The Great Lake trout is grayish in color, light or dark according to its surroundings; and the body is covered with round paler spots, which are gray instead of red. The dorsal and caudal fins are marked with darker reticulations, somewhat as in the brook-trout. This noble species is found in all the larger lakes from New England and New York to Wisconsin, Montana, the Mackenzie River, and in all the lakes tributary to the Yukon in Alaska. We have taken examples from Lake Bennett, Lake Tagish, Summit Lake (White Pass), and have seen specimens from Lake La Hache in British Columbia. It reaches a much larger size than any _Salvelinus_, specimens of from fifteen to twenty pounds weight being not uncommon, while it occasionally attains a weight of fifty to eighty pounds. As a food-fish it ranks high, although it may be regarded as somewhat inferior to the brook-trout or the whitefish. Compared with other salmonoids, the Great Lake trout is a sluggish, heavy, and ravenous fish. It has been known to eat raw potato, liver, and corn-cobs,—refuse thrown from passing steamers. According to Herbert, "a coarse, heavy, stiff rod, and a powerful oiled hempen or flaxen line, on a winch, with a heavy sinker; a cod-hook, baited with any kind of flesh, fish, or fowl,—is the most successful, if not the most orthodox or scientific, mode of capturing him. His great size and immense strength alone give him value as a fish of game; but when hooked he pulls strongly and fights hard, though he is a boring, deep fighter, and seldom if ever leaps out of the water, like the true salmon or brook-trout."