308 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



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. Gill-rakers 10 + 13, rather long 

 and slender, nearly as long as eye, toothed. Fins small. Pectorals 

 and ventrals short, the ventral appendage three-fifths the length of the 

 fin; caudal strongly forked, on a slender peduncle. Head 4; depth 4. 

 B. 13-14. Pyloric coeca very few and large, 63 (45-80); scales 25-127- 

 29. D. 10; A. 13-14 (developed rays). L. 15 inches. Weight 3-8 

 pounds. A. small salmon, ascending streams in the fall to no great dis- 

 tance. Abundant from San Francisco northward. 



(Salmo Msutch Walbaum, Artecli Pise. 1792, 70: Salmo Tcysutsch Blocli & Schneider, 

 1801, 407: Salmo sanguinolentus Pallas, Zoogr. Ross. Asiat. iii, 379: Oncorliynchus san- 

 gidnoJentus Giintlier, \\, 160: Oncjrhynchus lycaoclon Giinther, vi, 155, iu part: Salmo 

 scouleri Suckley, MoDogr. Salmo, 94 : Salmo isuj^yitch Ricliaidson, Fauna Bor.-Amer. 

 iii, 224, 1S:>6: Salmo tsuppltch Giinther, vi, 118 (not of Jordan, Proc. U. S. Nat. Mus. i, 

 72^ \Sli,=^ Salmo purpurattis); Oncorhynchus tsuppitch, Jordan, Forest and Stream, Sep- 

 tember 16, 1880, 130.) 



** Gill-rakers comparatively long and numerous (30 to 40 in number) ; scales large, 

 in about 130 series. 



503. O. nerSca (Walbaum) Gill & Jordan. — Blue-hack Salmon; Bed-fish; Frazer's 

 lUver Salmon; Sugk-eye Salmon; Krasnaya Ryba. 



Color clear bright blue above; sides silvery, this hue overlying the 

 blue of the back ; lower fins pale, upper dusky ; no spots anywhere in 

 adults in spring; the young with obscure black spots above; males 

 deep crimson red in the fall ; the fins blackish, the caudal then often 

 speckled with black; young breeding males {'■'' KennerlyV^) often sharply 

 spotted. Body elliptical, rather slender. Head short, sharply conic, 

 pointed, the lower jaw included. Maxillary rather thin and small, ex- 

 tending beyond eye. Teeth all quite small, most of them freely mova- 

 ble; vomer with about G weak teeth, which grow larger in fall males, in- 

 stead of disappeariug. Preopercle very wide and convex; opercle very 

 short, not strongly convex. Preopercle more free behind than in 0. 

 chouicha. Ventral scale about half the length of the fin; caudal fin nar- 

 row, widely forked; anal fin long and low; dorsal low. Flesh deep red. 

 Males becoming extravagantly hook-jawed in the fall, the snout being 

 then prolonged and much raised above the level of rest of head, the 

 lower jaw i)roduced to meet it. Mandible 1^ in head, in fall males. If in 

 females; snout 2^ in head, in fall males, 3^ in females. Head 4; depth 4. 

 Gill-rakers as long as eye, more numerous than in any other of our sal- 

 mon, usually 16-23. B. 14-f 13. D. 11; A. 14; scales 20-133-20; 



