280 A HISTORY OF RECENT CRUSTACEA 
near its base. The ocular and antennal segments are 
more or less movable. and not covered by the carapace. 
The two pairs of maxille are rather simply constructed. 
The first of the two series of legs are closely applied to the 
mouth, and from this circumstance the sub-order has re- 
ceived its appellation of ‘mouth-footed.’ According to Pro- 
fessor W. K. Brooks, in his Report on the Challenger Stoma- 
topoda, there are about sixty species known of adults, and 
an equal or greater number of larve, from the tropical, 
sub-tropical, and temperate waters of the Atlantic, Pacific, 
and Indian Oceans. Some of the species range over the 
whole of this area, while others are known from only 
a single restricted locality, almost a fourth of the species 
having been described from single specimens. They are 
usually found in very shallow water, only one or two 
species being reported from depths like a hundred and 
twenty fathoms. ‘The wide distribution of many of the 
species is undoubtedly due to the great length of their larval 
life, during which they swim at the surface, and are swept 
to great distances by the oceanic currents.’ On the other 
hand, the adults are extremely active in their movements 
and retiring in their habits, most of them being burrowmg 
animals, from which it results that they may long remain 
undiscovered even in localities where they are abundant. 
Some, like Sguilla empusa, which hunt far from their 
burrows, are often caught in nets and trawls, but ‘ others, 
such as Lysiosquilla excavatrix, are the Myrmeleons of the 
ocean, lying in wait for their prey, covered with sand, with 
only the tips of their eyes exposed, at the mouths of their 
very deep burrows, to the bottoms of which they dart at the 
least alarm.’ At a station where they were extremely 
numerous, Professor Brooks could scarcely capture one, till 
he devised the insidious plan of holding bait in one hand 
and a trowel in the other at the mouth of the burrow, and 
even so with his best speed the trowel often cut in two the 
retreating quarry, 
