CHAPTER XXI 
THE GRAYLING AND THE SMELT 
HE Grayling, or Thymallide.—The small family of 
Thymallide, or grayling, is composed of finely organized 
fishes allied to the trout, but differing in having the 
frontal bones meeting on the middle line of the skull, thus 
excluding the frontals from contact with the supraoccipital. 
The anterior half of the very high dorsal is made up of un- 
branched simple rays. There is but one genus, 7hymallus, 
comprising very noble game-fishes characteristic of sub-arctic 
streams. 
The grayling, Thymallus, of Europe, is termed by Saint 
Ambrose “the flower of fishes.”” The teeth on the tongue, 
Fie. 249 —Alaska Grayling, Thymallus signifer Richardson. Nulato, Alaska. 
found in all the trout and salmon, are obsolete in the grayling. 
The chief distinctive peculiarity of the genus Thymallus is the 
great development of the dorsal fin, which has more rays (20 
to 24) than are found in any of the Salmonide, and the 
fin is also higher. All the species are gaily colored, the dorsal 
fin especially being marked with purplish or greenish bands 
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