HERMIT-CRABS 265 
well fitted to make the best of their surroundings, the body be- 
coming modified to suit the peculiar conditions under which they 
live. In those which inhabit shells the abdomen becomes spiral, 
in conformity to the 
convolutions of the 
shell. All the ab- 
dominal appendages 
are more or less 
atrophied ; the sixth 
pair become like 
hooks, and _ these 
fasten to the colu- 
mella of the shell, 
keeping the crab 
securely attached to 
it. In the female 
some of the abdom- 
inal appendages 
are hair-like and are 
adapted to carrying 
the eggs. The tho- 
rax, being protected, 
is protruded from 
the shell at will. é 
Bho titsh ate OF Leth: ian loess eloiaioel voreas ay ast pao dneeeaager, 
are much larger than rai to fasten to the columella of the shell in which the hermit 
the others, and are : 
provided with claws (chele). The first right foot is usually much 
larger than the left, and, besides the usual functions of captur- 
ing and crushing prey, the claw, or hand, serves as an operculum 
to close the mouth of the shell when the crab retires completely 
within it. The small left hand is shaped to fill out the parts of 
the opening not covered by the right one, thus making a close 
fit. The next two pairs of feet end in simple hooks, and are 
used for walking and dragging the crab along when he travels. 
These crabs move about very fast, and the houses upon their 
backs seem no encumbrance. 
