HUNGERFORD: AQUATIC HEMIPTERA. 99 
Summary. In addition to the notes made by Martin and Bueno, the 
writer has been able to determine that while they may feed upon insects 
trapped upon the water, their main supply comes from emerging midges, 
Ostracods and mosquito wrigglers. They respond much more quickly to 
the activity beneath the surface than to that above. They may lay 175 
or more eggs and as many as eleven in one day. The average time for 
the incubation of the egg is 7 days, with a range from 4 to 22 days. 
Each nymphal instar requires on the average 2 days. Sometimes three 
or four, and in a couple of cases, only one day. The complete cycle from 
ege to egg, under the most favorable conditions, lasting 15 days. 
Family MESOVELIIDA® D. & S. 1867. 
A. TAXONOMY OF MESOVELIID:. 
Description. These are small, rather slender, green or yellowish- 
green bugs. The adults may be winged or apterous. (In the latter case 
the adults are distinguished by a broad connexvium.) Antenne four- 
segmented, filiform. Ocelli are present in the winged adults but “ob- 
solescent” in the wingless forms. Rostrum three-segmented, tarsi three- 
segmented. One genus, embracing one North American species. 
Historical review. Since these bugs were first made known to science 
in 1852 by Mulsant and Rey, through the descriptions of Mesovelia 
furcata, there have been added a few other species. Among them one de- 
scribed by F. B. White from the Hemiptera collected in the Amazons by 
Prof. J. W. Trail and named Mesovelia mulsanti. Uhler gave to our 
American species the name of M. bisignata and speaks of it at some 
length in Kingsley’s Natural History. 
Van Duzee regards this M. bisignata as a synonym of M. mulsanti 
White. ; 
The phylogenetic relationship of this little group has been somewhat 
of a puzzle. Mulsant and Rey assigned the genus to the family Hebride. 
Dohrn, 1857, in his Catalogus Hemipterorum places the Hebrids and 
Mesoveliids together under what he calls “Ductirostri” between the 
Mirids and Tingidids. Baerensprung, 1860, in the “Catalogus Hemip- 
terorum Europe” includes the Gerrids, Veliids, Hebrids and Hydro- 
metrids in the family Hydrometride. Douglass and Scott, 1867, were 
» the first to disengage them from the others. These writers set them 
- apart with tribal rank. On the whole, writers assigned them to kinship 
_ with the various waterstriders and treaders until Reuter, 1912, removed 
them toa position with the Hebride# between the Reduviide and Nabide. 
General Habits. These insects are to be found upon and about the 
blankets of alge, duck meat, etc., floating upon quiet pools. They take to. 
_ the open water when disturbed, where they are able to propel themselves 
with a fair degree of success, running upon the water rather than row- 
ing, as do the Gerrids. 
Genus MESOVELIA M. & R. 1852. 
. Besides the characterization given under the family description, and 
Ms in the absence of the original generic description, there is little that the 
_ writer dares to hazzard concerning the generic description. The pro- 
