Jordan and Evermann, Fishes of North America. 517 



Family LXV. THYMALLID^E. 



(THE GRAYLINGS.) 



The family contains Salmonoid fishes, with ripe ova first discharged 

 within abdominal cavity, branchiostegals 8-10 (11), pyloric cceca in mod- 

 erate number, a rather long dorsal fin, whose anterior half is composed 

 of simple unbranched rays, and posterior half of bifurcate or little 

 branched rays, epipleural spines to anterior ribs, and the parietal bones 

 meet ing at middle and excluding frontals from supraoccipital. (Gill.) 

 The graylings agree closely with the Salmon-Ida! in external characters 

 and in habits. They, however, differ notably in the structure of the 

 skull, as above indicated. The conventional statement that they are 

 intermediate between the trout and the whitefishes is not borne out by 

 the skeleton. One genus with about five species; beautiful fishes of the 

 rivers of cold or Arctic regions, active and gamy and valued as food. 

 (Thym-aUida:, Gill, Proc. U. S. Nat. Mus., 1894, 121.) 



238. THYMALLUS, Cuvier. 



(GRAYLINGS.) 

 Tliymnllm, CUVIKR, Regne Anim., Ed. 2, n, 300, 1829, (thy mall us); not Thymalm* LATREILLE, 



1802, a genus of Coleoptera. 

 Choregon, MINDING, Lehrbuch, Naturgesch. Fische, 119, 1832, ((thymallus). 



Body oblong, compressed, little elevated. Head rather short ; mouth 

 moderate, terminal, the short maxillary extending past the middle of the 

 large eye, but not to its posterior margin. Teeth slender and sparse on 

 the maxillaries, premaxillaries, and lower jaw ; vomer short, with a 

 small patch of teeth ; teeth on the palatines ; tongue toothless, or nearly 

 so. Gill openings wide. Branchiostegals 7 or 8. Gill rakers short and 

 rather stiff. Suborbital and preorbital bones narrow. Scales small and 

 loose, 75 to 100 in the course of the lateral line. Dorsal fin very long and 

 high, mostly in advance of the ventrals, of about 20 rays, of which the 

 anterior half are slender and simple, most of the others simply bifid; 

 adipose fin small; caudal fin forked ; anal fin small, of 10-15 rays. Pseu- 

 dobranclme well developed. Air bladder very large. Pyloric appendages 

 about 15. Coloration brilliant, the dorsal with red or blue spots. Beau- 

 tiful fishes of the fresh waters of northern regions. (Thymallus, an 

 ancient name of the Grayling, the fish having the odor of thyme, ftvpof.) 



a. Dorsal fin very high, with 22 to 24 rays. BIGNIFER, 787. 



aa. Dorsal fin moderate, of 19 to 21 rays. ONTARIENSIS, 788. 



787. THYMALLUS SIGNIFEB (Richardson). 



(ARCTIC GRAYLING ; POISSON BLEU.) 



Head 5i ; depth 4| ; eye 3. D. 24 ; A. 11 ; scales 8-88 to 90-11 ; cceca 18. 

 Body elongate, compressed, highest under the anterior portion of the 

 dorsal. Head rather short, subconic, compressed, its upper outline con- 

 tinuous with anterior curve of the back. Mouth moderate, the maxillary 

 extending to below the middle of the eye; maxillary 6 in head; jaws about 



*Those who think that the two names (Thymalus and Thymallus) conflict, may take the name 

 Choregon in place of Thymallus. Gill. 



