216 THE CARTILAGINOUS FISHES 



fastest liners for hours together for the chance of anything in the 

 way of food that may be cast overboard. The White Shark is 

 proverbially ravenous, and will devour anything from a bag of 

 cinders tossed over the side of a vessel to an unfortunate swimmer 

 who ventures in its vicinity. Not only the jaws but the tongue, 

 palate, and throat of this terrible fish are lined with finely serrated 

 teeth, which are broadly triangular in shape and without basal 

 cusps. It swallows enormous quantities of food at a time, its 

 great stomach being capable of expansion to accommodate it. 



The Blue Shark (Carcharias glaucus) is usually from 12 to 15 

 feet in length, though out in mid-ocean specimens are some- 

 times encountered which are quite 25 feet long. On the other 

 hand, the Blue Shark that visits the British coasts in the summer 

 months does not usually exceed 6 or 8 feet. It is a slender, grace- 

 ful fish, white underneath and a slaty-blue colour above ; and, 

 in common with the other members of the CarchariidcB family, is 

 distinguished by an absence of spines in the dorsal fins, of which 

 there are two, one in front of the pelvic fins and the second opposite 

 the anal fin. The Blue Shark is a fierce hunter, pursuing and 

 killing quantities of smaller fishes. It often follows the shoals of 

 herring and mackerel, and does a great deal of mischief by cutting 

 and tearing the fishing nets to get at the fish caught within them. 



The Topes and the Hounds are members of the same family. 

 They are small sharks, the British Tope (Galeus canis) being generally 

 from 4 to 6 feet long, while the Hounds are rather smaller. The 

 Smooth Hound (Mustelus lavis), so called from the skin being 

 smoother to the touch than is generally the case with the sharks, 

 is also sometimes called the Spotted Hound, on account of the 

 whitish spots which mark the back. 



The Topes, the Hounds, and the Dog-fishes (Scylliida) are all 

 ground-feeding fishes, and haunt the shallow waters round the 

 coast, preying on small fishes, molluscs, Crustacea, and starfishes. 

 Certain species are often very abundant near our shores, and are 

 frequently exceedingly troublesome to the fishermen, as they take 

 the bait from the hooks on the long lines, and cut and break the 

 nets, often doing a great deal of damage. One of the worst offenders 

 in this way is the small Spotted Dog-fish, called by fishermen on 

 some parts of the coast " Robin Huss." Dog-fishes have a variety 

 of curious local names. The Smooth Hound is a " Bastard Rig," 



