Adaptations of Fishes rp 
they die. If lifted out of the water, the slimy hagfish at once 
slips out and swims quickly away. In gill-nets in Monterey 
Bay great mischief is done by hagfish (Polistotrema stouti). It 
is a curious fact that large numbers of hagfish eggs are taken 
from the stomachs of the male hagfish, which seems to be 
Fie. 58. —Hagfish, Polistotrema stouti (Lockington). 
almost the only enemy of his own species, keeping the numbers 
in check. 
The Swordfishes.—In the swordfish and its relatives, the sail- 
fish and the spearfish, the bones of the anterior part of the 
head are grown together, making an efficient organ of attack. 
The sword of the swordfish, the most powerful of these fishes, 
has been known to pierce the long planks of boats, and it is 
supposed that the animal sometimes attacks the whale. But 
stories of this sort lack verification. 
The Paddle-fishes.—In the paddle-fishes (Polyodon spatula and 
Psephurus gladius) the snout is spread out forming a broad 
paddle or spatula. This the animal uses to stir up the mud 
on the bottoms of rivers, the small organisms contained in 
mud constituting food. Similar paddle-like projections are 
developed in certain deep-water Chimeras (Harriottia, Rhino- 
chimera), and in the deep-sea shark, Muitsukurina. 
The Sawfishes.—A certain genus of rays (Pristis, the saw- 
fish) and a genus of sharks (Pristiophorus, the saw-shark), pos- 
sess a similar spatula-shaped snout. But in these fishes the 
snout is provided on either side with enamelled teeth set in 
sockets and standing at right angles with the snout. The 
animal swims through schools’ of sardines and anchovies, strikes 
