164 ZOOL06T. 



laid in shallow holes made in the gravel of streams. The 

 extreme young is banded and called parr; when about a 

 year old, and of a bright silvery color, before descending 

 the rivers to the sea, it is called a smolt; after its return 

 from the sea into fresh water it goes by the name of grilse; 

 and finally, after returning a second time from the sea, it 

 assumes its name of salmon. The trout (Sahno fontinalis) 

 also breeds in the autumn and early winter; it is not mi- 

 gratory, living permanently in streams and ponds. 



An allied family embraces the smelt (Fig. 207). The 

 capelin (Mallotus villosus) is valuable as bait in the cod 

 fishery. It spawns in the summer. The males are distin- 



Fig. 207.— The Smelt, Osmerus mordaxr, one half natural size. 



guished by a prominent lateral ridge along the sides of the 

 body, and are more numerous than the females. 



The carps (Cyprinus), shiners, and minnows abound 

 everywhere in the Northern States in ponds and weedy 

 streams. The breeding habits of the dace (Rhinichthys 

 atronasus) are interesting. The females spawn over " nests" 

 or shallow depressions two feet m diameter in running 

 brooks about a foot deep; the male passes over the eggs fer- 

 tilizing them; then the pair bring small pebbles which are 

 dropped over the eggs, until layer after layer alternately of 

 eggs and pebbles are deposited, when a heap is formed, the 

 young hatching out and remaining among the pebbles until 

 old enough to venture out into the stream. The dace is 

 closely allied to the chub (Semotilus rhotheus, Fig. 209). 



