FISHERMEN'S OWN BOOK. 



123 





Hammerhead Shark— The Shark's Mouth— Shark Fishina;. 



The above engraving illustrates a species of shark of the genus Zygccna. 

 The head is flat with the orbits extending laterally in a most extraordinary 

 manner, flexible and doubled on themselves in the foetus, but standing out at 

 right angles and to a greater distance as age advances. On the end of 

 these lateral processes are the large eyes. Appleton's Encyclopcedia states 

 that "this strange form of head is found in no other vertebrate, and only in 

 some dipterous insects {diopsis, 6^<r.), and in many decapod crustaceans 

 whose eyes are at the end of long pedicels. The snout is truncated so that 

 the head resembles a double hammer ; the nostrils are on the front border 

 and have a small nasal flap ; the teeth are alike above and below, com- 

 pressed pyramids, sometimes with serrated external basal ridge and a mesial 

 tooth in both jaws, tail pits distinct. It attains a length of twelve feet or 

 more, and is grayish above, with head nearly black, and whitish below ; the 

 iris is yellow ; the first dorsal is high, triangular, falcate, and toward the 

 upper part of the back, the second smaller and near the tail. It is found in 



