LIBRARY

HEMIPTERA 271
13. Rostmm four-segmented. Tarsi two-segmented. Stout little bugs with
short, subequallegs. (Velvet Water Bugs.) . " HEBRID..!E
Rostmm three-segmented. Tarsi three-segmented, the basal segment
very small. Elongate, slender bugs with long slender legs for running
on the surface of the water. (Water Treaders.). . MESOVELIIDlE p.295
H. Head cylindrical or narrowed and strongly extruded or produced.
Front legs moderately to distinctly enlarged, :raptorial. Beak often
short, stout, curved, and fitted for a predacious habit . 15
Head usually broad and deeply inserted into the pronotum, and front
legs usually slender. If the head is cylindrical or the front femora
are enlarged and spined, then the membrane has only five simple
longitudinal veins or the corium is deflected into a cuneus. 18
15. Head strongly constricted behind the eyes, the ocelli located on the
posterior, subglobose lobe. Pronotum divided into three distinct
lobes by transverse sutures. (Gnat Bugs.) • . ENICOCEPHALIDlE p. 284
Head less distinctly or not at all bilobed. Pronotum not divided into
three lobes 16
16. Fourth antennal segment thickened. Front femora tremendously enlarged,
subtriangular. (Ambush Bugs.) . . PHYMATIDlE p.284
Fourth antennal segment not thickened, slender. Front femora scarcely
to moderately incrassate 17
17. Pro sternum with a longitudinal, transversely striated, stridulatory
groove between the coxre which receives the tip of the rostrum. Rostrum
three-segmented. (Assassin Bugs.) . . REDUVIID..!E p.285
Prosternum without a longitudinal stridulatory groove. Rostrum usually
four-segmented. (Damsel Bugs.) . NABIDlE p. 288
18. Hemelytra with a distinct fracture subapically on the coriwn, producing
a deflected cuneus . 19
Hemelytra without a distinct cuneus 22
19. Ocelli absent. (Leaf Bugs, Capsids.) MIRIDlE p. 293
Ocelli present 20
20. Tarsi two-segmented. Body less than 172 mm. long MICROPHYSIDlE
Tarsi three-segmented. 21
21. Rostrum four-segmented. Apical two antennal segments without long,
erect hairs. (Jumping Tree Bugs.) . ISOMETOPIDlE
Rostrum three-segmented. Apical two antennal segments usually beset
with long hairs or bristles. (Flower Bugs.) ANTHOCORlDlE p. 292
22. Antenna;: four-segmented 23
Antennre five-segmented 34
23. Ocelli absent 24
Ocelli present 28
24. Hemelytra reduced to short pads without trace of membrane. Flat·
tened species with strongly asymmetrical male genital organ. Highly
modified for an ectoparasitic, blood-sucking existence . 25
Hemelytra complete or at least with some indication of membrane.
Not modified as ectoparasites . 26
25. Eyes absent. Ctenidia present, at least on the head and antennre.
Hemelytra consisting of nonarticulating pronotal pads. Front legs
greatly enlarged. (Bat Bugs.) . . POLYCTENIDlE p. 289