Tanks No. 23 and 24. 
45 
Fig. 70. Ilia nucleus, */2 nat. size. 
they pinch violently every thing which is held out at them. In the 
Aquarium they have been seen to break thick glass tubes. 
Out of the water all Shore-crabs can live a considerable time and 
move about with as much agility as in their native element. 
Besides all these Crustaceans 
with five pairs of legs ( Decapocla ) we 
must refer to a genus belonging to 
the Siomatopoda. This is the Mantis- 
prawn (Squilla mantis, Fig. 74), 
a „slender, agile, and predacious 
animal which in the shape and po¬ 
sition of its claws greatly resembles 
a well known insect, the Praying 
Mantis (Mantis religiosa ). Its legs 
have claws that close like the blades 
of a penknife on its handle; and 
it can dart them at its victim with 
great force and velocity, like the 
predacious insect which it resembles. 
The Mantis-prawn is a very clean 
animal, and almost constantly oc¬ 
cupied in carefully cleaning all 
parts of its body. It may be seen 
(Tanks 23 and 24), in all sorts of 
attitudes, performing its toilet. Now 
the eyes and feelers, now the mouth 
and its appendages, now the legs 
and joints of the body are brushed 
and stroked, till no foreign particle 
is left adhering to them. 
Up to the present we have 
dealt with Crustaceans of consid¬ 
erable size, which at once strike 
the eye; but now we must spend 
a little time over their smaller kin. 
The large group of the Crustacea 
comprises such a variety of forms, 
that only those zoologists especially 
studying this group have a con¬ 
ception thereof, and by far the 
greater number of species are un¬ 
suitable for exhibition in an Aqua¬ 
rium. This is due in some to their 
smallness, often accompanied by 
entire transparency, so that they cannot be seen with the naked eye; in 
some to their secluded habits. We must confine ourselves to those more 
striking forms which are occasionally exhibited in the Aquarium. 
Almost all the year round most of the tanks, especially No. 7 and 
11 , contain swarms of very minute, lively shrimps, which play about 
Fig. 72. Lupa hastata , i /2 na t. size. 
