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 vdshes 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. jAumbea "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 lifer history deals 

 with European species. 



