246 



ZOOLOGY 



to the outside of other fishes, sucking their blood, or else 



they may penetrate into 

 the body cavity. They 

 do not bite, because they 

 have no lower jaw, and 

 are known as "round- 

 mouthed' eels. 1 Lam- 

 preys are found in the seas 

 and in the rivers of the 

 temperate zones. They 

 occur on our Eastern 

 coast and ascend rivers ; 

 others live in the lakes of 

 New York, in the Great 

 Lakes, and in the Missis- 

 sippi valley. In Europe 

 they are much esteemed 

 as food. 



The Selachians include 

 the sharks and rays, all 

 inhabitants of the sea. 

 They may be distin- 

 guished from the bony 

 fishes by the rough skin, 

 beset with spines, and by 

 the cartilaginous skele- 

 ton. We have a num- 

 ber of sharks on our 

 Northeastern coast, of 

 which the dogfishes and 

 the sand-shark are the 



i Fig. 229. 



