480 Bulletin 47, United States National Museum. 



summer, moving up, without feeding, until the spawning season, by which 

 time many of those which started first may have traveled more than 

 1,000 miles. It ascends the Snake River to the neighborhood of Upper 

 Salmon Falls, where it spawns in October and November. In the Salmon 

 River of Idaho it ascends to the head waters, more than 1,000 miles from 

 the sea, where it spawns in August and early September when the water 

 has reached a temperature of about 54 F. After spawning, most or 

 all of those which have reached the upper waters perish from exhaus- 

 tion. It is by far the most valuable of our salmon. It has lately been 

 introduced into eastern streams. (Tschatvytscha, better spelled by earlier 

 writers Tchaviche, the vernacular name in Alaska and Kamchatka.) 

 Salmo tschawytscha,WAivAVM, Artedi Piscium, 71, 1792, rivers of Kamchatka; after the Tschawi- 



tscha of KRASCHENINNIKOW, Descr. Kamchatka, 178, 1768, and the Tschawytscha of PENNANT, 



1792; BLOCK & SCHNEIDER, Syst. Ichth., 407, 1801. 



Salmo orientalis, PALLAS, Zoogr. Ross.-Asiat., in, 367, 1811, Kamchatka. 

 Salmo quinnat, RICHARDSON, Fauna Bor.-Amer., in, 219, 1836, Columbia River; and of many 



writers. 



Fario argyrew, GIRARD, Proc. Ac. Nat. Sci. Phila., 1856, 218, Cape Flattery; Fort Steilacoom. 

 Salmo conftuentus, SUCKLEY, Ann. Lye. Nat. Hist. N. Y., December, 1858, and Pacific R. R. Surv., 



xn, Part 2, 334, 1860, Puyallup River, near Fort Steilacoom; (Coll. Suckley); and 



Monogr. Salmo, 109, 1861 (1874). 

 Salmo argyreus, SUCKLEY, Pacific R. R. Surv., xn, Part 2, 326, 1860, and Monogr. Salmo, 110, 



1861 (1874). 



Oncorhynchus quinnat, GUNTHER, Cat., vi, 158, 1866; JORDAN, Proc. U. S. Nat. Mus., 1878, 69. 

 Oncorhynchm orienlalis, GUNTHER, Cat., vi, 159, 1866. 

 Oncorhynchus choMcha,-\ JORDAN & GILBERT, Synopsis, 306, 1883. 



776. ONCORHYNCHUS KISUTCH (Walbaum). 



(SILVER SALMON; KISUTCH; SKOWITZ; HOOPID SALMON; COHO SALMON; BIELAYA RYBA; QUISUTSCH.) 

 Head 4 ; depth 4. B. 13 or 14. Pyloric coeca \>ery few and large, 63 (45 

 to 80) ; gill rakers 10 + 13, rather long and slender, nearly as long as eye, 

 toothed; scales 25-127-29. D. 10; A. 13 or 14 (developed rays). Body 

 rather elongate, compressed. Head short, exactly conical, terminating in 

 a bluntly pointed snout, which is longer and broader than the lower jaw; 

 head shorter than in a young Quinnat of the same size. Interorbital 

 space broad and strongly convex. Opercle and preopercle strongly con- 

 vex behind; the preopercle very broad, with the lower limb little devel- 

 oped; cheeks broad. Eye quite small, much smaller than in young 

 Quinnat of the same size, Suborbital very narrow, with a row of mucous 

 pores along its surface; maxillary slender and narrow, but extending 

 somewhat beyond the eye. Teeth very few and small, only two or three 

 on the vomer ; those on tongue very feeble. Fins small. Pectorals and 

 ventrals short, the ventral appendage three-fifths the length of the fin ; 

 caudal strongly forked, on a slender peduncle. Bluish green ; sides sil- 

 very, with dark punctulations ; no spots except a few rather obscure on 

 top of head, back, dorsal fin, adipose fin, and the rudimentary upper 

 rays of the caudal ; rest of the caudal fin unspotted ; pectorals dusky 

 tinged ; anal with dusky edging ; sides of head without the dark color- 

 ation seen in the Quinnat ; males mostly red in fall, and with the usual 



t An unsuccessful attempt at respelling the barbarous-looking word " tschawylscha." 



