46. SALMONID^ ONCOEHYNCHUS. 307 



rich in spring, becoming paler in tLe fiill as the spawning season 

 approaches. Head 4; depth 4. B. 15-lG to 18-19, the number on the 

 two sides always unlike. D. 11; A. IG. Gill-rakers usually 9 + 14 

 {i. e., 9 above the angle and 14 below). Pyloric coeca 140-185. Scales 

 usually 27-14G-29, the number in a longitudinal series varying from 

 140-155, and in California specimens occasionally as low as 135. Verte- 

 brie GG. L. 3G inches. Usual weight in the Columbia Eiver 22 pounds, 

 elsewhere lG-18 pounds, but individuals of 70-100 pounds have been 

 taken. Ventura Eiver to Alaska and Northern China, ascending all 

 large streams; especiall}' abundant in the Columbia and Sacramento 

 Eivers, where it is the principal salmon. Upwards of 30,000,000 i^ounds 

 are now taken yearly in the Columbia Eiver. It ascends the large 

 streams in spring and summer, moving up, without feeding, until the 

 spawning season, by which time many of those which started first may 

 have travelled more than a thousand miles. After spawning, most or 

 all of those which have reached the ujjper waters perish from ex- 

 haustion. It is b}^ far the most valuable of our salmon. It has lately 

 been introduced into many eastern streams. 



{Salmo Uhaivytscha* Walbaum, Artedi Pise. 1792, 71: Salmo orientalis Pallas, Zoogr. 

 Eoss. Asiat. iii, 3S7, 1S11-'31: Salmo quinnat Eich. Fauna Bor.-Ainer. iii, 219, and of 

 ■writers generally: Oncorhnnchus quinnat Giiuther, vi, 158: Oncorhijnchus orientalis 

 Giiutber, vi, 159: Oncorhynchus quinnat Jordan, Proc. U. S. Nat. Mus. i, 69: Fario 

 aryyreus Girard, Acad. Xat. Sci. Phila. 1S5U, 218: Salmo quinnat, conjluen'tm, and 

 argyrcus Suckley, Mouogr. Salmo, 105, 109, 110: Salmo tschawytscha Bloch & Schneider, 

 1801,407.) 



aaa. Scales comparatively large, about 130 (125-135) in a longitudinal series; pyloric 

 coeca 50-80. 



502. O. kiSHtcSl (Wall).) Jor. & Gilb. — Silver Salmon; Kisutch ; SJcowitz; Hoopid 

 Salmon; Coho Salmon; Bielaya Ryba. 



Bluish green; sides silvery, witli 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 un- 

 spotted ; pectorals dusky tinged ; anal with dusky edging; sides of head 

 without the dark coloration seen in the Quinnat; males mostly red in 

 fall, and with the usual changes of form. Body rather elongate, com- 

 pressed. 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 convex behind ; 

 the preopercle very broad, with the lower limb little developed. Cheeks 



* A barbarous spelling of the word "ehouicha" wliich we have thought proper to 

 eimplify. 



