were dragging themselves out upon the ledge, in
frantic haste, when the diabolical swarm reached the surface. But
Hobbo, who was the slowest swimmer, was merely clutching at the rock
when the water boiled all about him in a froth of light. A pair of
huge, pincer-like claws seized him by the neck, and another pair by
one arm, plucking him back. His convulsed face stared upward for an
instant, and then, with a choked scream, he was dragged under. He
disappeared in a swirl of pale blue, frantically waving claws, and
eyes, and feelers, and black-fringed, chopping mouths.

Beside himself with rage and horror, Grom stabbed down wildly into the
whirling struggle, and his example was followed at once by Loob and
young Mo. Some of their random blows went home, and as one or another
of the gigantic crabs turned over in its death-throes, its nearest
fellows seized it, tore it to pieces, and devoured it.

But A-ya, who had taken no part in this vengeance, now snatched Grom
by the arm, shrieking wildly:

"Look! They are coming out!"

Recovering their senses, the three half-maddened men stared about
them. On every side the gigantic crabs--some with claws eight or ten
feet long, and eyes upon the ends of long waving stalks--were crawling
up upon the ledge.

The ledge, fortunately, was of some width. At its landward end it rose
into a mass of tumbled rocks perhaps twenty or thirty feet above the
water. Toward this post of vantage the adventurers fought their way,
striking and thrusting desperately with their spears as the monsters,
crowding up from the water on either side, snatched at them with their
terrible mailed claws. Over and over again one or another of the party
was seized by the foot or the leg; but his companions would beat the
long, jointed limb to fragments, or drive their spear-points deep into
the awful, drooling mouth, and set him free.

At last, bleeding from many wounds, they reached the end of the ledge
and clambered to the top. Here but three or four of the giant
crustaceans tried to follow them. These were easily speared from
above, and hurled back disabled among their ravening kin. And the
whole swarm, apparently forgetting their intended victims as soon as
they were out of reach, fell to fighting hideously among themselves
over the convulsed bodies of these wounded. The lower portion of the
ledge, and the water all about it, was a crawling mass of horror that
seemed to froth with blue light. And a confuse