TELEOSTOMI 



213 



then cover them by a heap of stones placed layer upon layer to a height 

 of about 10 inches. 



The salmon (Salmon 1 idee) are found in Europe and North America. 

 They live in salt water, but often go thousands of miles to their fresh-water 



Fig. 175. Showing longitudinal section of the nest of a dace with the 

 male and female fish in the nest. The stream flows in the direction indi- 

 cated by the arrow at the upper left-hand corner of the figure. (Bull. 

 Bureau of Fisheries, 1908.) 



breeding places. The white fish and the various species of fresh-water 

 trout belong to this group and are delicious food fishes. The red-spotted 

 brook trout is most widely known, and is found from Maine to Dakota. 

 On account of its great cunning the trout is much sought by sportsmen, and 

 is fast becoming exterminated hi its natural haunts. 



Fig. 176. Eel (Anguil'la chrysypa). (Bull. U. S. F. C., 1895.) 



Eels (Anguil'lidce) have the body greatly elongated, having many ver- 

 tebrae, and being almost cylindric (Fig. 176). They have no ventral fins 

 and the " pharyngeal and opercular bones are more or less deficient." 

 The scales are minute or entirely wanting and the skin is very slimy. They 



