1917] Hungerford—Life-History of Mesovelia mulsanti White 73 
oppositus by having the lateral-posterior margins of the thorax 
crenulated and by the prominent yellow band across the elytra. 
In general form it is nearest to zonatus Dall. but the latter has a 
much larger hind femora while the femora of phyllopus is only 
normally swollen. The scallops in the foliation of the hind tibiz 
are rather shallow and much shorter than in zonatus. Specimens 
have been examined from Virginia south to Florida and Texas. 
THE LIFE-HISTORY OF MESOVELIA MULSANTI WHITE. 
By H. B. Huncerrorp, 
Cornell University, Ithaca, N. Y. 
Among the most familiar inhabitants upon the surface of our 
ponds and quiet pools are the “‘skaters.”’ These long-legged 
creatures that deport themselves with such ease and agility upon 
the surface of the waters have been noted by even the most casual 
observers. Their size and movements have forced at least a passing 
notice, but there are a number of small related species that 
escape all but those who look intently. Among these smaller 
forms is the little green Mesovelia mulsanti. It wears the brightest 
livery of them all, for the young and the apterous forms of the 
adults display varying degrees of green coloration, while the winged 
ones are even more conspicuous on the floating blankets of green 
algze because of the silvery whiteness of their wings. 
These insects measure only from four to five millimeters in 
length but are so distinct from other bugs in structure that they 
have been regarded as a distinct family. 
At various times in the past they have been found in. our col- 
lections associated with the Hebridew, Gerridw, Hydrometride and 
Veliide but at last have been segregated as the family Mesoveliide. 
The species here treated is the only one reported from the United 
States, but it is a widely distributed form. 
It is at home in the haunts of the marsh-treader on the floating 
vegetation growing in the shallow waters of the pools, where the 
clumps of sedge spread their slender stems upon the water from 
the bordering bank, where young cat-tails spring up and green 
alge carpet the surface of the waters. 
