250 HETEROPTERA. 



waters of our lakes, or perhaps in the wide reaches of slow 

 moving streams. It is a very active species, and skips and 

 jumps in pursuit of its prey, or perhaps in playfulness. Very 

 little is known about it beyond the fact that it extends from 

 Canada at least as far south as South Carolina. It com- 

 monly occurs in the apterous, but the winged form seems 

 not rare under favorable conditions. The nymph of this spe- 

 cies together with that of Rheumatobates were described by 

 Ashmead as Halobatopsis beginii. 



Trepobates pictus H. S. ; 1848 (?), Wanz. Ins., viii, p. Ill, figs. 

 882, 883. 



Here we have the most common and widespread species 

 of the tribe, another dweller on the tranquil bosom of the 

 lakes, where it skims solitary far from the shores or congre- 

 gates in little shoals in some friendly sheltering cove, both 

 young and old ^in one group. The winged form, very rare 

 in this latitude, has a most peculiar (and to the collector, 

 annoying) habit of breaking off its wings for about half their 

 length, thus leaving several of the abdominal segments ex- 

 posed, a trick which is not limited to one sex only. Judging 

 from aquarium breedings, unlike the Gerrini known to me, 

 the eggs are glued fast in masses embedded in a transparent 

 glue, and in nature are probably attached to some solid 

 object at the edge of the water. In due course the white 

 eggs grow darker and hatch ; the young nymph casts its skin 

 five times before attaining its full growth in some five weeks 

 or so. It ranges from Canada to Central America, in whose 

 tropical climate the winged form is far more abundant than 

 with us. 



Rheumatobates rileyi Bergroth ; 1892, Ins. Life, iv, p. 321. 

 Kb. teuuipes Meinert ; 1895, Ent. Medd., p. 7. 



In these two species we have two of the most peculiar of 

 the water-striders. The female shows no striking peculiari- 

 ties of structure, but the males in both (as well as in all the 

 other species of the genus) have most peculiarly formed and 

 distorted antennae, which have all the appearance of being 

 designed for prehensile organs. Thus far I have been un- 

 successful in discovering their peculiar function, but should 



