ADAPTATIONS OF AQUATIC INSECTS IgIt 
devoid of insect life, the exceptions being a few chironomid 
larvee which have been dredged in deep water, and fifteen 
species of Halobates (belonging to the same family as our 
familiar pond-skaters ), which are found cn warm smooth seas, 
where they subsist on floating animal remains. 
Between tide-marks may be found various beetles and col- 
lembolans, which feed upon organic debris; as the tide rises, 
the former retreat, but the latter commonly burrow in the sand 
or under stones and become submerged, for example the com- 
mon Anurida maritima. 
Insect Drift.— Seaweed or other refuse cast upon the shore 
harbors a great variety of insects, especially dipterous larve, 
staphylinid scavengers and predaceous Carabidee. On_ the 
shores of inland ponds and lakes a similar assemblage of in- 
sects may be found feeding for the most part on the remains 
of plants or animals, or else on one another. During a strong 
wind, the leeward shore of a lake is an excellent collecting 
ground, as many insects are driven against it. On the shores 
of the Great Lakes insects are occasionally cast up in immense 
numbers, forming a broad windrow, fifty or perhaps a hundred 
miles long. Needham has described such an occurrence on 
the west shore of Lake Michigan, following a gale from the 
northeast. In this instance, a liter of the drift contained 
nearly four thousand insects, of which 66 per cent. were crick- 
ets (Nemobius), 20 per cent. Acrididze, and the remainder 
mostly beetles (Carabidee, Scarabzeide, Chrysomelide, Coc- 
cinellide, etc.), dragon flies, moths, butterflies (dAnosia, 
Pieris, etc.) and various Hemiptera, Hymenoptera and Dip- 
tera. A large proportion of the insects were aquatic forms, 
such as Hydrophilus, Cybister, Zaitha, and a species of caddis 
fly; these had doubtless been carried out by freshets, while the 
butterflies and dragon flies had been borne out by a strong 
wind from the northwest, after which all were driven back to 
the coast by a northeast wind. While some of these insects 
survived, notably Coccinellide, Trichoptera, Asilida, Acridi- 
ide and Gryllide, nearly all the rest were dead or dying, in- 
