The majority of them had two fins just behind the gill slits, typical fish tails and blunt, sloping heads. But now and then I saw a spined monster that was queerly unlike its fellows.
Instead of two front fins, these unique ones had two vacant round holes. The head looked as though it had forgotten to grow; its place was taken by an eyeless, projecting, shield shaped cap. And there was no tail.
Glad to find something to distract my half crazed thoughts, I studied the nearest of these.
They moved slower than their tailed and finned brothers, I noticed. I wondered how they could move at all, lacking in any kind of motive power as they seemed to be.
Next instant the secret of their movement was made clear!
Out of the empty fin holes of the creature I was studying crept two long, powerful looking tentacles. But these were not true tentacles. There were no vacuum discs on them, and they moved as though supported by jointed bones—like arms.
The arms ended in flat paddles that resembled hands. These threshed the water in a sort of breast-stroke, propelling the body forward.
Shortly after the arms had appeared, the spiny head cap was cautiously extended a few inches forward from the main shell. Further it was extended as the head of a turtle might slowly appear from the protection of its bony case. And under it—
"Professor!" I screamed wildly. "My God! Look!"