116 MALACOP. ABDOM. SALMON FAMILY. 



they thus present themselves in a greater number 

 of interesting relations than most olher tribes of 

 fishes. The most characteristic feature of the family 

 is the peculiar form of the posterior dorsal fin, 

 wliich is fleshy or adipose, and destitute of rays. 

 In the typical species, the series of teeth is very 

 complete ; the vomer, palatine, and maxillary bones 

 are beset with angular teeth directed backwards ; 

 there is a row of similar teeth on each side of the 

 tongue, and another series on the lower jaw. When 

 the mouth is closed these rows alternate with each 

 other, every interstice is thus filled up, and the re- 

 sult is the formation of as perfect an instrument for 

 seizing and retaining small objects as can well be 

 imagined. The number given above as British, 

 constitute nearly one-half of the family, viewed in 

 relation to Europe. Africa and America produce 

 other forms, but these deviate somewhat from the 

 typical structure. The most characteristic members 

 are the most northerly fresh-water fish with which 

 we are acquainted. 



Gen. LXY. Salmo. — Vomer, palatine, and maxil- 

 lary bones with sharp stout teeth ; gape wide ; 

 branchiostegous rays varying in number, but always 

 exceeding eight ; dorsal fins two, the ventrals oppo- 

 site the middle of the first dorsal, the adipose dorsal 

 opposite the anal. 



(Sp, 124.) S. salar. The appearance of this well 

 known fish is familiar to all. It is the largest spe- 

 cies of the genus, sometimes exceeding eighty pounds 

 in weight, although the average weight is not above 



