THE PICKED DOG-FISH. 
203 
good idea of tlie powers of this tremendous weapon when wielded by the iron muscles of 
the Thresher : — 
“One morning during a calm, when near the Hebrides, all hands were called up at 
three a. m. to witness a battle between several of the fish called Threshers or Fox Sharks and 
some swordfish on the one side and an enormous whale on the other. It was in the middle of 
summer, and the weather being clear and the fish close to the vessel, we had a fine opportunity 
of witnessing the contest. As soon as the whale’s back appeared above the water, the 
Threshers, springing several yards into the air, descended with great violence upon the object 
of their rancor, and inflicted upon him the most severe slaps with their long tails, the sounds 
of which resembled the reports of muskets fired at a distance. 
“ The swordfish in their turn attacked the distressed whale, striking from below, and thus 
beset on all sides, and wounded, where the poor creature appeared, the water around him was 
dyed with blood. In this manner they continued tormenting and wounding him for many 
hours, until we lost sight of him, and I have no doubt that they in the end completed his 
destruction.” This strange alliance of two different fish against a marine mammal is a truly 
curious circumstance, and may have a deeper meaning than appears on the surface. 
The food of the Thresher consists mostly of fish, and in the stomach of one of. these 
creatures taken off the coast of Cornwall were found a quantity of young herrings. The color 
of the Thresher is dark slaty-blue above, and the same color, but mottled with white, below. 
It abounds in all warm seas, and in summer is one of the most abundant kinds on our 
New England coast. It is also occasionally taken on the Pacific coast. The Thresher is 
the only representative of its family. 
The family of Sand Sharks includes one genus and three species, of which CarcJiarias 
americanus is the more familiar form. It is a small voracious Shark, rather common on our 
Atlantic shores. 
The family of Porbeagles is well known through its very familiar representative, the 
Mackerel Shark {I sums glaucus). 
A species, allied of the genus Lamna , was lately discovered at Wood’s Holl, Mass. It is 
a large and fierce creature. 
A large spotted species of the Whale-shark family inhabits the California waters. 
The family which embraces the P ort J ackson Sharks is represented in California seas by 
Cestracion francesci. 
Another family in this connection is known as the Cow-shark family, having one species 
which ranges from Cape of Hood Hope to California. It is named “Perlous,” and is of the 
genus Heptangus. 
Among some other Sharks, the Picked Dog-fish deserves notice, on account of the 
curious weapons from which it derives its name. 
In front of each dorsal fin is placed a strong and sharply pointed spine, or pike, which has 
caused the fish to receive its popular name in most parts of the coast. The word is a dissyl- 
lable, and pronounced Pick-ed. On some of the shores it is called the Bone Dog, and on 
others it is known by the name of the Hoe. 
These, spines form aggressive weapons of a rather formidable character, the fish having 
the capability of directing a blow with wonderful accuracy. Mr. Couch says, that he has 
known the Picked Dog-fish able to pierce a finger if laid on its bead, and never to miss its 
aim. When about to strike, it bends its body like a bow, and suddenly lashes out in the 
intended direction. It is a very common species, especially during the herring season, as it 
follows tbe shoals of those fish for the purpose of feeding on them. Even the tiny, quarter- 
grown young, not half the size of their intended prey, instinctively follow the herrings, though 
it is manifestly impossible that they should be able to eat them. 
Tbe Picked Dog-fish is destructive to the fishing trade, not only on account of its large 
appetite and the number of fish it consumes, but because it cuts the hooks away from the lines 
with its sharp teeth. As, moreover, itjs extremely plentiful, some twenty thousand having 
