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THE FISHES OF THE NORTHERN SEAS 



Chimsera. 



All the foregoing groups are included in the class of bony fishes. 



That strange fish the sea-cat, or chimsera (Chimcera monstrosa), 

 represents, on the other hand, a totally distinct section — the Holocephali. This 

 fish, which ranges throughout the Atlantic and North Pacific, bears on its head 

 the curious crown-like structure from which it derives its popular title of " king 

 of the herrings." 



A third, and at the present day far more important, section of 



the class — the Elasmobranchii — includes the predaceous sharks and 

 rays. Although sharks are most numerous within the tropics, many of them range 

 into temperate seas. Among those which occasionally put in an appearance in 



Sharks. 



BASKING SHARK. 



British waters, the most striking is the great blue shark (Carcharias glaucus), 

 which reaches a length of 25 feet and is found in both the Atlantic and the Pacific. 

 The tope (Galeus vulgaris), which belongs to the same family and has nearly the 

 same distribution, is much smaller, rarely exceeding a length of 7 feet. The strange- 

 looking hammer-head (Zygoma malleus) is a cosmopolitan species, whose chief 

 peculiarity is sufficiently indicated by its name. Of more normal form is the 

 smooth hound (Mustdus vulgaris), which measures from 3 to 6 feet in length, and 

 differs from the tope by having the second dorsal fin much smaller than the first. 

 It is less common in British waters than its cousin the tope. 



The largest shark of the North Atlantic is the basking species (Cetorhinus 

 maximus), a fish with a huge mouth but very small teeth. This shark is quite 

 harmless to the larger denizens of the sea, except when attacked, and subsists on 



