flying. The wings are merely fins,
enormously enlarged, and these give the fish its great size, rather
than does the body itself. It is the whipping spike-armed tail of the
devil fish that is to be feared, aside from the fact that the rush of a
monster might swamp a small boat.

It was two or three of these devil fish that were now floating in the
water above Tom and his companions, who were grouped about the stern of
the disabled submarine.

"They won't attack us unless we disturb them," said Tom through his
telephone, speaking to Ned and Koku. "Keep still and they'll swim away.
I guess they're trying to find out what new kind of fish our boat is."

All might have gone well had not Koku acted precipitately. One of the
devil fish, the smallest of the trio, measuring about ten feet across,
swam down near the giant. It was an uncanny looking creature, with its
horns swirling about in the water and its bone-tipped tail lashing to
and fro like a venomous serpent.

"Look out!" cried Tom. But he was too late. Koku raised his axe and
struck with all his force at the sea beast. He hit it a glancing blow,
not enough to kill it, but to wound it, and immediately the sea was
crimsoned with blood.

The devil fish was able to observe under water better than its human
enemies, and it was in no doubt as to its assailant. In an instant it
attacked the giant, seeking to pierce him with the deadly tail.

These tails are not only armed with a tip of horn-like hardness, they
are also poisonous, and their penetrating power is great. Fishermen
have sometimes caught small sting rays, which are a sort of devil fish.
Lashing about in the bottom of a boat a sting ray can send its tail tip
through the sole of a heavy boot and inflict a painful wound which may
cause serious results.

The beast Koku had wounded was trying to sting the giant, and the
latter, aware of his peril, was striking out with the axe.

"Look out, Tom!" called Ned through his telephone, as he saw one of the
two unwounded devil fish swirl down toward the young inventor. Tom
looked up, saw the big, horrible shape above him, and jabbed it with
the sharp, steel bar. He inflicted a wound which added further to the
crimson tinge in the sea, and that fish now attacked Tom Swift.

In another instant all three divers were fighting the terrible
creatures, that, knowing by instinct they were in danger, were using
the weapon with which nature had provided them. They lashed about