TROUT. SM ELT. GRAYLING. 105 



26. The Salmon Trout, Salmo trutta,](ke the salmon has 

 reddish flesh, and the caudal fin crescent shaped : but it has on all 

 the under parts of the body, a great number of black spots, ocellate, 

 or in form of an X ; it sometimes weighs eight or ten pounds. 



27. The Common Trout, Sulmo fario, has the caudal fin 

 but little notched, and its flesh is white: (Fig. 52.) it is also 

 distinguished by the brown spots on the back, and red spots sur- 

 rounded by a bright circle on ^, 52 



the flanks, which are on a 



ground, the shade of which 



varies from white and golden 



yellow, to a deep brown. It is 



commonly from twelve to fifteen 



inches in length, weighing about 



a pound; but it is sometimes 



met with of larger size. It inhabits rivers in the northern 



parts of Europe and the United States. Many other river 



Trouts are known, which are chiefly found in lakes and mountain 



streams, and which vary in their size and colours in each locality ; 



some naturalists regard them as different species, and others look 



upon them as simple varieties, resulting from age, food, and the 



quality of the waters in which they dwell. 



28. The SMELTS, Osmerus, also belong to the family of 

 Salmonides ; they differ from the preceding in the almost total 

 absence of teeth on the vomer, in the number of the branchios- 

 tegous rays, which is eight in place of ten, and in the absence of 

 spots on the body. They are caught in the sea at the mouths of 

 large rivers; their flesh is excellent. The Common Smelt, 

 Osmerus eperlanus, is small : it is ornamented with the most 

 dazzling silvery and light green tints. The skin is so exceedingly 

 thin that, under the microscope, the blood may be seen circulating 

 in the cutaneous vessels. 



29. The GRAYLINGS, Thymallus, have jaws like the Trout; 

 but the mouth is but slightly cleft, and the teeth are very fine. 

 They have the habits of the Trout, and their flesh is equally 

 esteemed. The Common Grayling, Salmo thymallus, is striped 

 blackish longitudinally : it attains a size of eighteen inches, and 

 in the spring, ascends several rivers of France and Italy. It is 

 especially met with in the pure, limpid waters of the mountains 

 of America and Switzerland. 



26. What are the characters of the Salmon Trout? 



27. What are the characters of the common Trout ? Where is it found ? 



28. What are Smelts? What are the characters ui' the common Smelt ? 



29. What are the characters of Graylings ? 



