ean was literally covered with lobster and crab shell, with the bones
of fish scattered here and there among them. A few bones of land animals
were mixed with the debris and Carnes gave a gasp as Dr. Bird pointed
out to him a diving helmet.

"We are on the right track," said the scientist grimly. He stepped to
the telephone and ordered the sphere raised to one hundred fathoms. The
ship moved forward along the coast until Dr. Bird again stepped to the
telephone and halted it. Before them yawned the entrance to the
underground tunnel. It was about two hundred feet high and three hundred
across, and their most powerful beams would not penetrate to the end of
it. A pile of debris could be seen on the floor of the tunnel and
Carnes fancied that he could see another diving helmet among the litter.
Dr. Bird pointed toward the side of the cavern.

"See those floodlights fastened to the cliff so that their beams will
sweep across the mouth of the tunnel when they are lighted?" he said.
"Apparently the cave is used as a prison and the light beams are the
bars. The creature is not at home just now or the bars would be up. My
God! Look at that, Carnes!"

Carnes stared and echoed the Doctor's cry of surprise. Clinging to a
shelf of rock which extended out from the wall of the cavern and half
hidden among the seaweed was a huge marine creature. It looked like a
huge black slug with rudimentary eyes and mouth. The thing was fifty
feet in length and fully fifteen feet in diameter. It hung there, moving
sluggishly as though breathing, and rudimentary tentacles projecting
from one end moved in the water.

"What is it, Doctor?" asked Carnes in a voice of awe.

"It is a typical trochosphere of the giant octopus, the devil fish of
Indian Ocean legend, multiplied a thousand times," he replied. "When the
octopus lays its eggs, they hatch out into the larval form. The free
swimming larva is known as a trochosphere, and I am positive that that
is what we see; but look at the size of the thing! Man alive, if that
ever developed, I can't conceive of its dimensions!"

* * * * *

"I have seen pictures of a huge octopus pulling down a ship," said
Carnes, "but I always fancied they were imaginary."

"They are. This monstrosity before us is no product of nature. A dozen
of them would depopulate the seas in a year. It is a hideous parody of
nature conceived in the brain of a madman and produced by some glandular