204 THE BLUE SHARK. 



but delicate tendrils entwined in almost inextricable complexity among the salt-loving 

 vegetation of the ocean, and their tiny inmates as yet imperfect and unborn. 



Water, which to these creatures contains the breath of life, gains access to the im- 

 prisoned sharkling, though two slight longitudinal apertures, one towards each end of 

 the egg ; and it is a very remarkable fact that in these waters the undeveloped young 

 are furnished with small external gills, which are afterwards absorbed into the system 

 a phenomenon curiously analogous to the structure of the tadpole. The substance 

 of the egg-shell, if such a term can be applied to the envelope which contains the young, 

 is of a moderately stiff horny character, becoming harder when dry, and of a semi- 

 transparent yellowish hue, not very unlike, though not so clear as the yellow portions 

 of tortoise-shell. 



For the escape of the young Shark, when strong enough to make its own way in the 

 wider world of waters, an outlet is provided in the opened end of the envelope, which 

 opens when pushed from within and permits the little creature to make its way out, 

 though it effectually bars the entrance against any external foe. When it first leaves 

 its horny home, the neophyte Shark bears with it a capsule, containing a portion of 

 the nutrimental principle of the egg, as is seen in the chicken of the common fowl, and 

 is enabled to exist upon this substance until it has attained the power of foraging for 

 itself, when the small remainder of the capsule is absorbed into the abdomen. 



The head of the Little Dog-fish is rather flat upon the top, there is a little spiracle 

 or blow-hole behind each eye, and the shape of the mouth is somewhat like a horse- 

 shoe. The general color of the body is pale reddish on the upper parts, covered with 

 many little spots of dark reddish brown ; below it is yellowish white. The length of 

 this species is about eighteen inches. 



THE second species shown in the engraving is called the ROCK Doc-FisH, because 

 it is often found on rocky coasts. From its superior size, it is also known by the name 

 of LARGE SPOTTED DOG-FISH, and on several coasts it goes by the curt and not eupho- 

 nious name of BOUNCE. 



The habits of this fish are so like those of the preceding species, that they need no 

 description. 



It may readily be distinguished from the little dog-fish by the large size and fewer 

 number of the spots, as well as by the shape of the ventral fins, which in this species 

 are nearly squared at the end, whereas in the former they are of a diamond-like form. 

 The color of the Rock Dog-fish is brownish gray above, without the red tinge of the 

 little dog-fish, and covered rather sparingly with large patches of blackish brown. 

 Below it is whitish. The length of a fine specimen will sometimes be nearly a yard. 



ANOTHER species of Dog-fish, namely, the BLACK-MOUTHED DOG-FISH, or the EYED 

 DOG-FISH {Pristidurus melanbstomus), is mentioned by Mr. Yarrell among the list of 

 British fishes. It may be at once distinguished from either of the preceding species 

 by its large snout, and a row of small flat and sharp-edged prickles, arranged in saw- 

 like fashion on the upper rim of the tail fin. The generic title Pristidurus, or Saw-tail, 

 is given to the fish in allusion to this peculiarity. Its color is light brown on the 

 upper surface, sprinkled with spots, the smaller of which are scattered irregularly, and 

 the larger arranged in four rows, two on each side. Its length is between two and 

 three feet. 



The . BLUE SHARK, so called from the fine slaty blue color of its skin, is a not 

 unfrequent visitor of our shores, and is the object of the deadliest hatred to the fisher- 

 men, who are sometimes doomed to see their fish stolen, their nets cut to pieces, and 

 their lines hopelessly ruined by this fish, without the least power of checking its 

 depredations. 



About the month of June, according to Mr. Couch's observations, this Shark makes 

 its appearance on our coasts, and has sometimes been so plentiful that nine or ten 

 have been taken by our fishing boats in a single day. As the fishermen are hauling 



