568 LOBSTERS. 
crustaceans when they are alarmed and go scuttling over the ground to their 
homes, holding up their claws and beckoning in all directions. 
WE now come to a singular group of crabs, which are remarkable for 
their soft and shell-less tails and the mode employed to protect them. From 
their solitary habits they are called HERMIT-CRABS, and from their extreme 
combativeness they have earned the title of SOLDIER-CRABS. 
The best known of these crustacea is the common HERMIT-CRAB of 
England (Pagurus Bernhardus), which is to be found plentifully on our 
shores. Like all its race, the Hermit-crab inhabits the shell of some 
mollusc, in which it can bury its unprotected tail, and into which it can retreat 
when threatened.with danger. The Hermit-crab usurps the deserted home 
of various molluscs, according to its size, so that, when young and small, it is 
found in the shells of the tops, periwinkles, and other small molluscs ; 
and when it reaches full age, it takes possession of the whelk-shell and 
entirely fills its cavity. 
To see a Hermit-crab fitting itself with a new shell is a very ludicrous sight. 
The creature takes the shell among its feet, twirls it about with wonderful ra- 
pidity, balances it as if to try its weight, probes it with the long antenne, and 
perhaps throws it away. Sometimes, however, when the preliminary inves- 
tigations have proved satisfactory, it twists the shell round until the tail falls 
into the opening, and then parades up and down for a little while. Perhaps 
it may be satisfied, and after twirling the shell about several times, whisks 
into it with such speed that the eye can scarcely follow its movements, 
Indeed it seems rather to be shot into the shell from some engine of pro- 
pulsion than to move voluntarily into the new habitation. When the 
number of empty shells is great, the Hermit is very fastidious, and will 
spend many hours in settling into a new house. 
In all these creatures the larger claw is very much developed; so that 
when the Crab has withdrawn into the shell, the claw lies over the entrance 
and closes it like a living 
door, which has the further 
advantage of being used as 
an offensive weapon. The 
footstalks on which the eyes 
are set are moderately long, 
stout, and jointed, and en- 
able their possessor to see 
in all directions. 
WE next take the second 
great division of the Crus- 
taceze, namely those which 
have long and _ power- 
ful tails. The LoBsTERS 
and SHRIMPS are examples 
of these creatures. In swim- 
ming rapidly through the 
water, the tail is the organ 
of propulsion which is em- 
ployed, and a glance at its form will soon explain its use. 
WE now come to the family of the Astacida, which includes two well- 
known -and very similar creatures, the fresh-water cray-fish, and the salt- 
water Lobster. The general shape and appearance of the LOBSTER is too 
well known to need any description. The vast numbers of Lobsters which 
are annually brought to the London markets are largely supplied from 
Norway, although there are many parts of oyr own coasts where these 
LOBSTER.—( Astacus gammarus.) 
