1856.] 217 



Notice upon the Species of the genus Salmo, of authors, observed chiefly in Oregon 



and California. 



By Charles Girard, M. D. 



In the 21st volume of the " Histoire Naturelle des Poisons," published in 

 1848, Valenciennes subdivides the genus Salmo of Artedi, Linnaeus, and others 

 into three genera: the salmons proper (^Salmo), the salmon trouts (Fario), and 

 the brook trouts (Salar), each characterised by the number and arrangement of 

 the vomerine teeth. 



This method we have applied to the species of the present synopsis, which is 

 but an abstract of a more elaborate memoir to be published shortly, accompanied 

 with figures of most of the species. 



Needless to say that the observations here recorded have all been made upon 

 specimens preserved in the Museum of the Smithsonian Institution. 



The sources whence specimens were obtained, are enumerated under each 

 special heading ; all being well known to the lovers and cultivators of Natural 

 History. 



Genus Salmo, (Artedi), Valenc. 



Gkn. char. Body fusiform ; head large ; mouth generally deeply cleft, and. 

 armed with conspicuous teeth. Pre-maxillary (intermaxillary) bones short and 

 rather situated upon the sides of the snout than upon its extremity ; the max- 

 illaries are attached behind them and composed of a single bone. The lower jaw 

 is strong, and terminates frequently into a small knob or tubercle, which, in 

 some species, acquires a very great developement. Strong and conical teeth, 

 disposed upon a single row, are implanted upon the dentary. A f-ew teeth on 

 the front of the vomer; none on the shaft of that same bone ; a single row of 

 them is also observed along the palatines, and two rows upon the pterygoids 

 and upon the tongue. There is one anterior dorsal fin, followed posteriorly by a 

 small adipose more or less thick. The caudal is well developed, and either 

 truncated posteriorly or slightly emarginated. 



Syn. Salmo, Artedi, Gen. Pise. ed. Walbaum, 1192, 58. Valenc. Hist. Nat. 

 Poiss. xxi. 1848, 166. 



The scales, on all the species, have that common character of being deprived 

 of those radiating grooves or furrows which extends from the organic centre of 

 the scale to its periphery. The concentric, or lines of growth, are the only ones 

 extant, and, in many instances (in Salmo and Fario, especially), they are inter- 

 rupted or else have become obsolete upon the posterior section of tha scales. 

 In many instances, also, they have disappeared from the organic centre itself, 

 which, under the microscope, appears perfectly homogeneous. Generally speak- 

 ing, their outline is subelliptical, elongated in the direction of the longitudinal 

 or horizontal axis of the body. Differences of minor value may be observed in 

 each species. 



1. Salmo scouleri. Rich. Faun. Bor. Amer. iii, 1836, 158 and 223. PI. xcvi. 

 Dekay New Y. Fauna, iii, 1842, 242. Storer, Synops. 1848, 194. 



The " Ekewan" of the natives of the Columbia river. Is identical with the 

 " Observatory Inlet salmon." A specimen collected by Dr. John S. Newberry, 

 under Lt. W. R. Williamson, in the Des Chutes river, a tributary of the Colum- 

 bia, 0. T. 



2. Salmo quinnat. Rich. Faun. Bor. Amer. iii, 1836, 219. Dekay, New Y. 

 Fauna, iii, 1842, 242. Storer, Synops. 1846, 196. Common Salmon of Lewis 

 and Clarke. 



Body fusiform in profile, compressed. Head forming about the fifth of the 

 entire length. Maxillary bone curved, extending beyond the orbit. Dorsal 

 region olivaceous, studded with irregular black spots ; dorsal and caudal fins 



