MOTIONS OF INSECTS. 365 
every-pool thus working their little legs with great rapi- 
dity, and moving about in all directions.—Some spiders 
also will not only traverse the surface of the waters, but, 
as you have heard with respect to one?, descend into 
their bosom. There are other insects moving in this 
way that are not divers. Of this kind are the aquatic 
bugs (Gerris lacustris, Hydrometra Stagnorum, Velia 
Rivulorum, &e., Latr.). The first can walk, run, and 
even leap, which it does upon its prey, as well as swim 
upon the surface. The second, remarkable for its extreme 
slenderness, and for its prominent hemispherical eyes— 
which, though they are really in the head, appear to be 
in the middle of the body—rambles about in chase of 
other insects, in considerable numbers, in most stagnant 
waters. The Velia is to be met with chiefly in running 
streams and. rivers, coursing very rapidly over their 
waves. The two last species neither jump nor swim. 
I am next to say a few words upon the motions of in- 
sects that burrow, either to conceal themselves or their 
_young. Though burrowing is not always a locomotion, 
I shall consider it under this head, to preserve the unity 
of the subject. Many enter the earth by means of fore 
legs particularly formed for the purpose. ‘The flat den- 
tated anterior shanks, with slender feet, that distinguish 
the chafers (Scarabeus, L.)—all of which in their first 
states live under ground, and many occasionally in their 
last—enable them to make their way either into the earth 
or out of it. Two other genera of beetles (Scarites and 
Clivina, Latr.)® have these shanks palmated, or armed 
2 Vor. I. 4th Ed. 473. b Prate XV. Fie. 5. 
