OSMERUS. FISHES. 401 



they return again to the sea. The fry when of sufficient size likewise leave the 

 fresh waters for the sea ; and it is for the protection of the fish when on their in- 

 stinctive journeyings, and the preservation of the samlets, that legislative enactments 

 have become necessary. 



S. trutta, Lin. The Salmon Trout. Body marked with brown 

 spots, of which those on the upper part are surrounded by a bright- 

 er circle ; beneath silvery ; flesh red. 18 inches long. Inhabits 

 European Seas. B. Block, pi. 21. 



This species ascends rivers like the salmon. 



S.fario, Lin. The Common Trout. Body with brown spots up- 

 on the back, red upon the sides, each surrounded by a paler cir- 

 cle ; a large spot on the operculi ; the adipose fin yellow, with a 

 brown border ; under jaw rather longer than the upper ; flesh 

 white. 12 to 17 inches long. Inhabits Rivers and Lakes in 

 Europe. E.Pe?m. Brit. Zool. iii. pi. 70. 



S. Hucho, Lin. Body sub-elongated, silvery gray, with numerous 

 round brown spots ; back dusky ; fins, except the ventral, which 

 is yellowish, pale purple, thickly spotted with brown ; tail forked. 

 2 to 5 feet long. Inhabits fresh waters of Europe Block, pi. 100. 



S. alpinus, Lin. Alpine Trout. Body marked with numerous 

 spots and points, black, red, and silvery, mixed with yellow, and 

 without a circle ; back tinged with olive-green ; the belly white ; 

 all the fins, except those of the back, are reddish, and the adipose 

 one is red on its edge. About a foot long. Inhabits Alpine 

 Lakes and Rivers. B. Shaw, v. pi. 103. 



S. Umbla, Lin. Body silvery, without spots; back tinged with 

 olive-brown ; fins pale olive ; tail forked ; scales very small. 

 About a pound or a pound and half in weight. Inhabits the Lake 

 of Geneva. Block, pi. 101. 



Gen. 2. OSMERUS, Artedi. Salmo, Lin. 



Mouth at the extremity of the snout ; head compressed ; scales 

 scarcely visible ; two dorsal fins, the second adipose, and 

 without rays ; the first more distant from the head than the 

 ventral fins ; two rows of scattered teeth on each palatine 

 bone ; branchial membrane with eight rays. 



O. eperlanus, Cuv. The Smelt or Sparling. Head semitranspa- 

 rent ; back whitish, with a shade of green ; sides variegated with 

 blue ; abdomen silvery. 3 to 6 inches long. Inhabits European 

 Seas. B. Penn. Brit. Zool. iii. pi. 72. 

 This species is found on the British coasts through the whole year, and rarely goes 



to any distance from the shores, except when it ascends rivers about the spawning 



season. It has a peculiar odour, which has been compared to that of a cucumber 



or violet. 



Gen. 3. COREGONUS, Artedi. Salmo, Lin. 



Mouth at the extremity of the snout, very little cleft ; head 

 compressed ; scales large ; two dorsal fins, of which the se- 

 VOL. i. c c 



