The octopus swims when forced to do so, using a weblike membrane which is seen to connect the base of the eight arms or by forcing water from its siphon. These arms, when extended, give the octopus a faint resemblance to an umbrella without a handle, and with very long supports. The octopus preys upon very small animals, particularly crabs. I have lain among the bowlders on the shores of the Californian islands and watched the octopus hunting. They selected the flood tide and crept near the shore, moving along slowly, on the watch for a species of Grapsus very common here, a land crab which occasionally enters the water. The crabs crept down to the water's edge, and often entered, and in this moment of incaution were pounced upon by the disagreeable creature so well named the devilfish. Sometimes they were caught at the very edge; a long, livid tentacle would come shooting out of the water like a flame and seize the victim. Despite its struggles, it was soon hauled in, the octopus immediately covering it with its umbrellalike bag, doubtless bringing its nippers into play. I have seen an octopus dash out of water two or three feet and scramble up the dry rocks with remarkable speed after an escaping crab. At these times the octopus can be caught by seizing it quickly, but some experience is required before one can grasp a large octopus and retain the hold, so disagreeable is the sensation of the snakelike tentacles winding about hand and arm. The very appearance of the octopus is like a horrible dream, and so intensely repulsive is the animal that in an actual test not one person in fifty who passed a tank containing an octopus with arms a foot long and a hideous striped body, could be induced to touch the animal, though assured that it was absolutely harmless and would merely squeeze the hand.