80 
BRITISH BEETLES. 
When ponds, &c., are dried up in the summer, the 
Dytincides take to the wing, flying by night or at the 
evening in search of fresh waters ; it is astonishing, 
however, with what a small supply of damp they will 
exist, aud the greatest “hauls” of specimens are 
often made out of the merest cupful of muddy water, 
the residue of some large pond, in which all the beetle 
occupants are congregated. They have been known, 
in flight, to dash against glass or lights, possibly mis- 
taking them for water. 
Water-beetles, as a rule, are fond of gathering 
round reeds and water-plants in the middle of 
ponds ; and, in dragging for them, the net should be 
scraped along banks, round any projecting wood or 
stones, and through aud under weeds. After doing 
so, it is a good plan to go over the same water again, 
in a reverse direction, as many specimens get dis- 
lodged, but not captured, by the first operation. In 
running streams, the beetles often congregate in little 
pools caused by eddies and backwaters, and shelter 
themselves on the quiet sides of arches. To show how 
readily they fly, it may be remarked that holes in 
gravel pits, when converted into pools by heavy rain, 
are soon tenanted by the large Dijtisci. 
The species of Dytiscus exhibit a great family like- 
ness, but are separated chiefly through the greater or 
less width, length, and sharpness of the forked pro- 
cesses of the coxae at the base of the two hinder legs. 
They are mostly found in stagnant waters, but many 
of their allies delight in running streams, and these 
latter are usually more metallic and variegated with 
light spots (Agabus maculatus, Plate III., Fig. 2). 
The larva of the common D. marginalis (Fig. 1, 
