There were eyes and nose and mouth placed on one side of that head—a face! There were even tabs of flesh or bony protuberances that resembled ears.

"Curious," muttered the Professor, staring. "It certainly looks human enough to talk. But it's only a fish, nevertheless. See—in the throat are gill slits."

"But the eyes! Look at them! They're not the eyes of a fish!"

And they were not. There was in them a light of reason, of intelligence. Those eyes were roaming brightly over us, observing the light, the equipment, seeming to note our amazement as we crowded to look at it.

The sphere rocked slightly. Behind the staring, manlike visitor there was a glimpse of enormous, crocodile jaws and huge, amethyst eyes. Instantly the head and arms receded, leaving an empty-seeming, lifeless shell. An impregnable fortress of spines, the thing drifted slowly away through the twisted loops of cable.

"It certainly looked like—" began Stanley shakily.

"The creature was just a fish," said the Professor shaking his head at the light in Stanley's eyes. "Some sort of giant parasite that inhabits the shells of other fish."

He opened the valve of the last air cylinder and seated himself resignedly on the bench.

"We have another half hour or so—"

All of us suddenly put out our hands to brace ourselves. The sphere had moved.