ange spectacle over, the adventurers
glanced about for a sight of the terrible sea suckers. But they need not
have feared. Lying in a huddled up mass toward the rear of the
_Porpoise_ were the dead bodies of the ugly creatures. The electricity
had finished them.

CHAPTER XXVII

ATTACKED BY AN OCTUPUS

They walked some distance away from the ship, for the land under the
water was easy to travel on. It looked exactly as if some beautiful
valley had suddenly been submerged in the middle of summer, when
everything was fresh and green.

They had gone perhaps a quarter of a mile from the _Porpoise_ when
Professor Henderson motioned to them that they had better return. On
their way back they passed what looked to be a large cave in the side of
a hill. Wondering what could be in it, Mark and Jack paused to peer into
the black opening.

The next instant two long white things, like slender serpents shot out.
With the rapidity of lightning they wrapped themselves, one about each
boy, and, before the horrified companions of the lads could do anything
the unfortunate youths were whisked out of sight into the cavern.

For a few seconds no one knew what to do. To rush in to the rescue of
the boys would have been foolhardy, as the terrible octupus, which they
knew had grabbed the lads, would have been a match for all of the
adventurers, unarmed as they were.

It would be necessary to return to the ship and come back with some of
the electric guns, which they had neglected to bring with them. In the
meanwhile the beast might, and probably would, kill Mark and Jack. But
there was nothing else to do.

The professor motioned for Andy to remain on the watch at the mouth of
the cavern, so as to be on hand in case he could help the boys, while
the others were hurrying toward the ship. Then, leading the way, the
Professor signalled for Tom and Bill to follow him.

They could not hurry much for the heavy suits and the resistance of the
water impeded their progress. But they made all the speed they could,
urged on by a terrible fear.

Meanwhile old Andy stood in front of the cave, hoping against hope that
there might be some way of aiding the boys. If it had happened above
water he would not have hesitated to rush in and give battle to the
beast, even though he was unarmed. If he had his knife now he would
venture in, at the risk of his life.

"Oh, why didn't I bring my gun along!" thought Andy regretfully.

His hand drop