20 SEA-FISH. 
less known, than that nereid which conceals itself 
in the convoluted end of the whelk-shell occu- 
Crab- pied by a hermit crab, and which, for 
worm want of a better English name, I have 
called “crab-worm,” just as the fisherman know 
the hermit as the “ crab-whelk.” There is usually 
an implied mutual advantage in these natural 
partnerships, or commensalisms ; but, although it 
is easy to understand that the worm gains at least 
shelter and probably some scraps of food, it is by 
no means obvious what profit accrues to the crab. It 
is surprising how long a worm will coil itself in the 
extreme corner of the shell; it is a fragile creature, 
and must be removed very carefully and without 
any rupture, else it is useless as bait. It is almost 
impossible to keep these worms alive for any time 
once they are removed from their natural asylum, 
damp weed, darkness and a cool temperature being 
essential ; therefore it is best to take craband all in 
the boat, breaking each shell as the worm is re- 
quired. There is not, of course, a worm in every 
shell, but there are on the average perhaps a score 
to fifty crabs. 
This curious creature, which carries its eight feet 
on its head, is, together with that other 
octopod the squid, much used in conger- 
fishing. It must first be cleaned of the ink-like 
fluid with which it thickens the water when evading 
its enemies or stalking its prey. Curiosity is fatal 
to both these cephalopods ; they may be speared by 
the light of a torch, or, a more usual way of taking 
them, caught on bare hooks jigged bencath a piece 
of china. I have caught them on three cod-hooks 
lashed in a triangle, when, off the Cornish coast, 
Cuttle 
