476 NATURAL HISTORY OF AQUATIC ANIMALS. 



mountain lakes it spawns in the spring, running into the rivers for that purpose. Its great 

 enemies at that season are the various species of sucliers and chubs, which feed, the former upon 

 its eggs, the latter upon the young Trout. So very destructive are the former in many trout lakes, 

 as Utah Lake, that the destruction or diminution of the suckers ought to be accompli.^hed by law. 



A parasitic tape-worm, Dibothrium cordiceps, Leidy, is said to frequently infest this species, so 

 as to render its flesh uneatable in the summer, in the Yellowstone Lakes. (Yarrow.) 



As a lood-flsh this Trout is excellent. Large numbers of the variety Senshawi are shipped to 

 the market of San Francisco. Attempts have been made to cultivate it iu parts of California, I 

 believe with success. A small hatchery has been established at Tahoe City for the purpose of 

 keeping stocked a small branch of the lake in which summer visitors may fish. 



In the opinion of the writer this species is likely to prove much more valuable for introduction 

 into Eastern waters than the Rainbow Trout. It is more active, more gamy, reaches a larger size, 

 and thrives iu a greater variety of waters. 



The Pao Grande Trout — Salmo spiliteus. 



This species is abundant in the headwaters of the Rio Grande, Eio Colorado, and their tribu- 

 taries, being the finest food-fish in New Mexico and Western Colorado. It has also been taken in 

 Bear River, and jirobably is found in most of the mountain streams of Utah, being in general 

 rather southern iu its distribution. It probably inhabits all streams within the circle of its distri- 

 bution, without regard to the direction in which they may flow. We have not seen this species in 

 life, and little distinctive is known of its habits. It is probably a compaiatively recent offshoot 

 from 8. purpuratus. As in other species, considerable variation is shown in specimens from difter- 

 ent localities. Its usual size is larger than that of S. purpuratus. 



The Dog Sal3ion — Oxcorhyxchus keta. 



This species, during the period of its run in the fall, generally goes by the name of "Dog 

 Salmon," under which name the males of the Silver Salmon, and even of the Quinnat, are often con- 

 founded with it. The Russians now, as in the time of Pennant, Pnllas, and Walbanm, call it 

 "Kayko," the name "Keta" (whale) being no longer in use. On Frazer River the name (ilusquara) 

 is now "Qualoch," at Seattle (Xisqually) "Ktla-why," and in the Chinnook jargon "Le-Kai."' 

 This species is very uniform in its size, and averages ten to twelve pounds. It ranges from the 

 Sacramento Ri\er to Bering Strait, where it seems to be especially abundant; it being the only 

 Salmon brought from there in a recent cruise of the revenneculter Corwin. It is seldom or never 

 seen in the rivers in spring. 



The Htemp-backed SjUlmon — Oncorhyxchus gorbuscha (Walb.) Gill & Jor. 



This species is known to the Russians still, as iu the time of Pennant and Pallas, bj" the name, 

 of " Gorbuscha," gorh meaning hump. The English speaking people call it generally the " Hump- 

 back Salmon," and often the "Dog Salmon." On Frazer River it is known as "Holia" or "Hone" 

 Salmon, and on Puget Souud as the "Haddoh." This is one of the smallest Salmon, not averaging 

 over four or five pounds, and probably never exceeding ten. It ranges from the Sacramento ! iver 

 to Alaska and Kamtchatka. In the Sacramento and Columbia it is only an estray, on the latter 

 river being sometimes called "Lost Salmon," In Puget Sound it runs in large numbers in late 

 summer and fall, like the Keta or Dog Salmon, ascending every little stream. Its run-in Puget 

 Sound takes place on alternate years, a fact which seems to be well established. It was very plenty 

 in 1879. None were noticed in 1880, but stragglers are occasionally taken during the year of 



