TELEOSTOMI 215 



Many kinds of flounders lie upon the left side upon the sea bottom. 

 The young flounder is somewhat cylindric, has an eye on each side, and 

 swims vertically like other fishes. The eye moves over by successive stages 

 until both eyes arc upon the upper or right side (Fig. 177). The mouth 

 also becomes crooked and the under side of the fish becomes white. The 

 upper side is colored and its color may be changed to suit the surroundings. 

 " The blind flounder does not adapt its color to its surroundings." 



The halibut sometimes attains a weight of 400 pounds and a length of 

 6 feet. It is found on both sides of the Atlantic Ocean. 



Sub-order Acanthop'teri. The spiny-rayed fishes constitute 

 a large group, including the greater number of the marine fishes 

 and many fresh-water species. The stickleback, perch, mullet, 

 mackerel, our river bass and sea bass, and our common sunfish 

 belong here. 



The perch is a carnivorous fish found both in fresh water and along the 

 seacoast and is widely distributed. These fishes spawn in winter, forming 

 nests in the gravel near the shore. 



Fig. 178. Large-mouthed black bass (Microp'lerus salmoides). (Bull. 

 U. S. F. C., 1900.) 



The bass and sunfish are common in our streams. The black bass is 

 found in clear running water from the St. Lawrence to Dakota and south to 

 Arkansas (Figs. 178, 179). Its length is 1 to 2 feet and it weighs from 2 to 

 7 pounds. It varies in color, the adult being olive green. It is a great 

 game fish. The sunfishes have short compressed bodies. They are 

 carnivorous, gamy, and usually brightly colored. 



The green sunfish (Lepo'mis cyanell'us), common in streams east of the 

 Mississippi, makes a nest of gravel in the shallow water and deposits several 

 thousand eggs, which the male guards. 



The seventy species of mackerel (Scom'brida:) are all marine. In early 

 summer great schools appear on the shores from Greenland south to Cape 

 Hatteras. The young from one female number from 500,000 to 600,000. 



