536 



THE OCEAN WORLD. 



length, of a general silvery colour, spotted with brown. It inhabits 

 the North Sea, living on molluscs and crustaceans ; occasionally, as if 

 to justify the title which has been given it, levying heavy contributions 

 upoa the herrings. The Callorhynchus Ausifalis is found in the 

 southern hemisphere, and greatly resembles, in its appearance and 

 habits, the northern species. In this species the end of the snout 

 terminates in a cartilaginous appendage, which is bent backwards at 

 the extremity, so as to acquire no small resemblance to a hoe. 



I- ig. 357. — Cliimaera monstrosa (tlie Arctic chiraaera). 



Of the Raiina, if we regard them as a sub-order of the Selachia 

 we would have at least half a dozen families. In Cephalopteridm 

 the head is truncated, with large, lateral eyes. In Myliobatidce it is 

 projecting, the pectoral fins extending like wings. In Trygonidce it 

 is enclosed by the pectorals. In the RaiidcE the body is rhomboidal, 

 tail without spine, but with two small dorsals near the top. In the 

 TorpedinidcE. the body is nearly round, the tail short and fleshy, with 

 two dorsals and a caudal fin. In RhinobatidoR the head is prolonged 

 into a sword-like organ, which is armed along its edges with strong 

 tooth-like spines. 



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