HUNGERFORD: AQUATIC HEMIPTERA. 139 
presenting to our view a successful catch impaled upon an upturned 
beak. Here it is held in mid air, till all the nutritive matter has been 
drawn from within the little bivalve and then it is discarded. If a quick 
flip of the beak fails to dislodge the carcass, the fore limbs strike it loose. 
Description of Stages. Mr. Bueno has published descriptions of four 
nymphal instars which he says is all of them. The writer has found 
more than this in some. Before publishing his results, he wishes again 
to rear this bug to see if here is variation, or whether apterous forms 
have less than winged, etc. No bugs have been secured for this purpose 
the past two seasons. Plate XII shows the nymphs, adults and eggs. 
Summary. The Microvelias winter as adults, place their white oval 
eggs on stones, etc., just above the surface of the water. They are pre- 
daceous creatures, feeding on organisms reared below and above the 
surface. Several generations are possible in a season. 
Genus RHAGOVELIA Mayr. 
These bugs inhabit rapid moving waters, one species R. plumbea “is 
a denizen of estuaries, bays and other brackish or salt waters on our 
southern coasts and about the Antilles.” They possess a most ingenious 
structural device for making progress on moving waters. Bueno has 
figured and explained the action of the rowing equipment of R. obesa. 
This species he says can be found in almost any swift streamlet in little 
congregations, weaving zigzags where the current is most rapid, swim- 
ming against it, or else sheltered in the eddy behind some projecting 
rock, where, in the latitude of New York, the rare, winged form is most 
likely to be found. 
As elsewhere noted, the long terminal tarsus of the middle leg is cleft 
and in this cleft is a tuft of ciliated hairs. The tarsus is in contact with 
the water along its entire length, with the slit vertical to the surface. 
When in this position the spread tuft of hairs projects beneath into the 
water and is a powerful auxiliary in swimming. See plate XI. When 
swimming under water the hair tuft is also expanded and is of great 
assistance. 
Mating. Bueno describes the mating in his paper in Can. Ent., Feb., 
1907. In June and July the schools are made up largly of sexes in copula, 
he says. 
The Nymphs. “The young nymphs betake themselves to sheltered and 
still nooks along the bank.” 
Behavior. Rhagovelia dives and swims well under water. To get be- 
low the surface the head is ducked down, and a few quick strokes with 
the middle legs submerges it. 
Feeding Habits. Feeds upon other insects. 
Genus VELIA Latr. 
We have four species in this country, but little is known of their 
biology. 
Habitat. So far as the writer knows, all of these dwell on flowing 
waters. Our information regarding the habits and life history deals 
with European species. 
