SALMONID^. — XXXIV. 7 9 



sides white ; centre of each scale silvery ; outside dotted, the 

 sides thus with faint pale stripes. Head 4 ; depth 3. D. 11. 

 A. 11. Scales 8-74-7. L. 18. Great Lakes, N., scarce. (An 

 Indian name.) 



81. THYMALLUS Cuvier. (OvjjiaWos, ancient name of the 

 Grayling.) 



189. T. signifer Richardson. American Grayling. Body 

 compressed, rather elongate; head short, subconic; mouth moder- 

 ate, the maxillary to middle of eye; jaws subequal; teeth on tongue 

 disappearing with age ; eye large, 3 in head ; a bare space on 

 breast ; gill rakers slender, X -}- 1 1 ; D. very high, especially in 

 males, highest in specimens from far North. Purplish gray, with 

 small black spots ; ventrals dusky, with pale Hues; dorsal highly 

 variegated, with crimson and dusky streaks and greenish and rose- 

 colored spots. Head 4f ; depth 4f. D. 20. A. 10. Scales 8-90 

 to 100-9. L. 18. Arctic America, in clear, cold streams. The 

 Michigan Grayling is var. ontariensis Cuv. & Val. Q=T. tricolor, 

 Cope), with rather longer head and lower dorsal, its height rarely 

 greater than depth of body ; in a few streams in N. Mich, and Mon- 

 tana; a remnant perhaps of the glacial fauna. (Lat., bearing a 

 banner.) 



82. SALMO (Artedi) Linnseus. (Lat., salmon, originally from 



salio, to leap.) 



(Besides the native Salmon, the following species have been 



introduced into waters within our limits : Salmo fario L., the 



" Brook-trout," or " Brown Trout," of Europe, with the vomerine 



teeth well developed and the scales rather large, about 120. Salmo 



gairdneri Richardson, the " Rainbow Trout " of California, similar 



to the last, and with about 130 scales. Salmo my kiss Walbaum, 



the Red-throated or Rocky Mountain Trout, with larger mouth 



and the scales about 1 75. Besides this, the great Salmon of the 



Columbia, the Quinnat or King Salmon, Oncorhynchus tschawytscha 



(Walbaum), has been introduced. This, the most valuable of all 



SalmonidcB, may be known by the presence of 16 anal rays, and by 



the black spots on back and upper fins. Its scales are about 145.) 



a. Marine Salmon, anadromous, with the vomerine teeth little developed, 



those on the shaft of the bone few and deciduous; scales large (lat. 1. 



120); C. deeply lunate, truncate in old age; no hyoid teeth; sexual 



differences strong; breeding males with the lower jaw hooked upwards, 



the upper emarginate or perforate, to receive its tip (Salmo). 



190. S. salar Linnseus. Common Salmon. Mouth moderate, 

 maxillary reaching past eye, 2^ to 3 in head ; preopercle with a 

 distinct lower limb. Brownish above, the sides silvery ; many black 

 spots on head, body and fins, these sometimes X-shaped ; sides with 



