The Squill seems to form a connecting link between the last and present
order. It is the only genus of the heterobranchial Crustacea in which
the eyes are placed on footstalks; the head, instead of being distinct,
appears in a great measure drawn into the corslet. It has been called
the Sea Mantis, from its bearing some resemblance to an insect of that
name, on account of the singularly-formed hooks with which two of its
foot-jaws are armed.
The species shown in the engraving is found in the Indian Seas; it is
the largest of the genus.
The shell with which these creatures are covered has very little
consistence, more resembling hardened skin than shell. They frequent
the sandy bottom of the sea.
[Illustration: _Squilla maculata._]
There is a small species which is found in fresh water, in which the
young, after the eggs are hatched, remain for some time in shelter
under the plates with which the body of the mother is covered.