808 CARTILAGINEI. — SQUALID^. 



Of the immense numbers of these fishes that 

 exist in the tropical seas, some idea may be 

 formed from the fact that in a single harbour 

 (that of Kingston), on the coast of Jamaica, from 

 one hundred to one hundred and fifty thousand 

 are destroyed annually. These are principally 

 young ones, which are taken in numbers at every 

 haul of the seine. On our own coast Sharks 

 (not, however, of this species) are very numerous. 

 Mr. Couch says of the Picked Dog-fish {Spinax 

 acanfkias), "I have heard of twenty thousand 

 taken in a seine at one time." These also were 

 young ones. But they have doubtless many 

 enemies ; and few of the young which swarm in 

 such incredible numbers, live to attain adult age 

 and dimensions. 



4. Spinacina, The Dog-fishes. These are 

 readily recognised by the spiracles or air-holes 

 which are placed, one on each temple, just 

 behind the eye. The dorsals in several of the 

 genera are each preceded by a strong spine. 

 This also is a numerous group, and includes most 

 of the British Sharks. 



5. Squaiinma. The Angel-fishes. This is the 

 form by which the Sharks merge into the Family 

 of the Rays. It is much depres-sed, with the 

 head broad, flat, and rounded ; the eyes are 

 placed on the summit of the head, and the mouth 

 at the extremity, while the gill-apertures are 

 beneath. The pectorals are enormous, as are the 

 ventrals, giving to the fish that rhomboidal outline 

 common to the Skates : the dorsals also are placed 

 far back. This subdivision is represented by a 

 British species, Squatina angelorum^ of large size 

 and great voracity, and held in no esteem. 



