14 NATURAL HISTORY. 



FIRST ORDER. 

 OSSEOUS FISHES .(Antkropteryyii.) 



The Percoides belongs to this class. Their bodies are 

 covered with rough scales ; the pectoral fins are composed 

 of five soft rays ; the jaws and palate are armed with 

 teeth ; the tongue is smooth. The most remarkable of 

 this family is 



The Common Perch (perca fluviatilis). Is about nine 

 inches in length sometimes a foot ; weighs from a half 

 to two pounds; greenish-brown above, with a golden 

 shimmer on the sides ; the ventral and anal fins are red. 

 Found in all the rivers and ponds of Europe, as well as 

 in Northern Asia and the United States, and is one of 

 the best fish brought to the table. Their spawn resem- 

 bles net-work. One perch will produce two hundred 

 and eighty thousand eggs. They swim very rapidly, and 

 keep at a certain depth. Their food consists of aquatic 

 insects and small fish, wherefore they are very injurious 

 to the young races of other species. Those who wish to 

 keep them, place them in ponds with white fish, because 

 the latter are of little worth. The perch is very tena- 

 cious of life, and, in winter, will survive a journey of 

 many miles. If the lightning flashes on the water in 

 which they live, they leap up to the surface. They are 

 easily caught by an angler who understands throwing 

 his hook to the proper depth in which they swim, as they 

 are very greedy, and catch at every thing near them. 



The Wolfs Perch (labrax lupus) is remarkable for 

 having the gill-coverings clothed with scales and spines. 

 The length is three feet ; weight thirty pounds ; blue- 

 green above : white below, with a silver-like spot on each 



