40, SALMONID^ SALMO. 313 



moderate; caudal fin distinctly thougb not strongly forked, more deeply 



incised than in any other of our species of Fario. Scales compraatively 



large. Coloration bluish above, the sides silvery; everywhere above 



l)rofusely but irregularly spotted, the spots extending on the sides and 



on the vertical fins ; spots on caudal small ; belly nearly plain; sea-run 



s])eciniens nearly plain silvery; males with red lateral band and blotches. 



Head 4 ; depth 3*. D. 11 ; A. 10; scales 21-135-20, varying considerably, 



the highest number noted being on the typeof '■'■Fario ncwherriP\ 33-14G- 



33. L. 24 inches. Weight J to 6 pounds. Streams west of the Sierra 



Nevada, from near the Mexican line (Rio San Luis Key) to Oregon ; very 



abundant, and subject to many variations in size, form, and color. 



(Gibbons, Proc. Cal. Acad. Nat. Sci. 1855, 36; Guuther, vi, 119; Sucldey, Monogr. 

 Salmo, 129; Jordan, Proc. U. S. Nat, Mus. i, 75: Fario (jairdneri Girard, U. S, Pac. 

 K. R. Sur%\ Fish, x, 313 (uot Salmo gairdneri Rich. ) : Fario neivherrii Girard, Proc. 

 Acad. Nat. Sci. Phila. 1858, 224 : Fario clarkii, Girard, Proc. Acad, Nat. Sci. Phila. 

 219 (uot iS", clarkii Rich.): Salmo masoni Sucliley, Mouogr. Salmo, 134.) 



cc. Caudal fm truncate (iu the adult). 



506. S. gairdneri Rich. — Steel-head; Hard-head ; Salmon Trout. 



Body rather stout, not very deep mesially, but with the caudal pe- 

 duncle thick. Head comparatively short and rather slender, in the 

 females small, in the males the jaws more or less prolonged ; maxillary 

 rather narrow, the small eye nearly above its middle; lower jaw in- 

 cluded ; upper jaw iu males emarginate at tip and at junction of premax- 

 illary. Teeth rather small, those on the vomer in two long, alternating 

 series, which are about as long as the palatine series. Preopercle 

 rather wide, with the lower limb short; opercle moderate. Gill-rakers 

 short and thick, 8+12 (essentially as in our other species of Fario). 

 Ventral appendage not half the length of the fin. Tail wide, squarely 

 truncate in the adult, somewhat emarginate in the young. Flesh rather 

 I)ale. Bones much firmer than in the Oncorhynchi. Color blue above; 

 sides silvery; head, back, upper fins, and tail more or less densely cov- 

 ered with black spots; belly usually unspotted ; males with colors height- 

 ened, the back greenish; a broad llesh-colored lateral band, deep red 

 on the opercles; fins not red; no red on the membrane of lower jaw; 

 B. 12-11; D. 11; A. 12; scales 20-135-20; pyloric cajca 42; vertebrae 

 38-f20. L. 30 inches. Sacramento River and northward. A large 

 trout, abounding in the mouths of the rivers, reaching a weight of 20 

 pounds. It spawns later than the salmon, and is found in the rivers, 

 spent, at the time of the spring salmon run. It is tlien nearly useless 

 as food, but at other times similar iu quality to other trout. 



(? Salmo mykiss Walbaum, Artedi, Pise. 1792, 59, aiiparcntly confused with S. purpur- 

 aim: ? Salmo muikini Bloch &, Schneider, 419: Salmo jjurpuratus GUnther, vi, IIG: Salmo 



