102 



FISH GALLERY. 



viduals of from twelve to fifteen feet are of very common occurrence, 

 but some of the species attain a much larger size and a length of 

 25 or more feet. Such large specimens are very dangerous to 

 man. 



The species of Galeocerdo (Case 33 : two large specimens of 

 G. arcticus, fig. 91, in the middle of the Gallery) also attain to a very 



Fig. 91. 



Galeocerdo arcticus. (From the Indo-Pacific and Atlantic Oceans.) 

 The figure of the tooth is of the natural size, and taken from a specimen 



11 feet long. 



[Case 34.] large size, and belong to the most dreaded of their kind. On the 

 other hand, the Tope (Galeus) is a diminutive form, found on the 

 British coast (G. canis), but spread over nearly all the temperate 

 and tropical seas, and is common in California and Tasmania. The 

 Hammerheads (Zygoma) (Case 34) have the same powerful dentition 

 as the Carcharias, and although they do not attain to the same 

 large size, they belong to the most formidable fishes of the ocean. 

 The peculiar form of their head is quite unique among fishes, the 

 anterior part being produced into a lobe on each side, the extremity 

 of which is occupied by the eye. By far the most common is 

 Z. malleus, which occurs in nearly all tropical and subtropical seas. 

 The "Hounds" (Mustelus) are small Sharks, abundant on the 

 coasts of all the temperate and tropical seas ; two of the five species 

 known occur on the coasts of Europe, viz. M. la?vis and M. vulgaris. 



