308 
CARTILAGINEI. — SQUALIDiE. 
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 
acanthias), 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. Squatinina, The Angel-fishes. This is the 
form by which the Sharks merge into the Family 
of the Rays. It is much depressed, with the 
head broad, fiat, 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. 
