CLASS V. PISCES: ORDER 1. SELACHIA. 
427 
THE FOX-SHARK. 
were found, and in another an entire bull's hide. Upon the latter a sailor remarked that the 
fish had swallowed a bull, but could not digest the hide ! This species is common throughout 
the Atlantic, especially the tropical portions of it, and is the scourge of the Mediterranean. 
The Fox-Shark or Thresher, C. vulpes^ is twelve to eighteen feet long, the tail nearly as long 
as the body ; it uses this mem- 
ber for attacking other animals 
by its powerful strokes. It is 
said even to attack the whale in 
this manner. It pursues shoals 
of mackerel, mossbunkers, and 
shad, and devours them in great 
numbers. It is common on both 
sides of the Atlantic. 
Other species are the Blue 
Shark, C. ceruleus, noted for its affection for its young ; four to six feet long : the Dusky Shark, 
C. obscurus, and the Ground Shark, C. littoralis, five to eight feet long ; all found on both sides 
of the Atlantic. 
Genus LAMNA : Lamna. — To this belongs the Porbeagle, L. Cornuhica, six feet long, and de- 
rivino; its name from a resemblance 
jT of form to the porpoise. Common 
in European seas. The Beaumaris 
Shark, L. Monensis, is seven to 
ten feet long, and found on the 
British coasts. It is considered by 
some as only a variety of the 
preceding. 
The Mackerel Porbeagle, X. 
punctata, is six to ten feet long, 
and is often called Mackerel Shark, 
from its habit of pursuing shoals of 
mackerel. It produces a kind of oil much valued by curriers ; found along the coasts of New 
York, and more abundantly on those of Massachusetts. The Long-tailed Porbeagle, L. cauclata, 
three to eight feet long, and is found on the coast of Long Island. 
Genus GALEUS : Galeus. — This includes the Penny Dog, G. vulgaris, called Tope and 
Miller'' s Dog in England, six feet long, voracious and destructive ; it yields a valuable oil ; is 
abundant on the coast of England in summer. 
Genus MUSTELUS : Mustelus. — To this belongs the Smooth Hound, M. Icevis, noted for the 
smoothness of its skin ; sometimes 
called Ray-7noiithed Dog ; two to 
three feet long; takes bait, but 
is less rapacious than other spe- 
cies ; common on the British 
coasts. 
The American Hound-Fish, 
M. canis, called Dog-Fish by 
our fishermen, is two to four feet 
long, feeds on Crustacea and sea-weed, and is found on the shores of Long Island. 
Genus SELACHUS : Selachus. — To this belongs the Basking Shark, S. maximus, tAventy 
to thirty-two feet in length ; one of the largest of the shark family ; it derives its name from a 
habit of basking lazily in the sun ; in England it is sometimes called Sun-Fish and Sail-Fish. 
It is often seen gliding along with its dorsal fin and upper jaw out of water, and has occasionally 
been taken for the sea-serpent. It is not voracious or dangerous. Found in the northern seas 
on both sides of the Atlantic. 
THE PORBEAGLE. 
THE SMOOTH HOUND. 
