Hemiptera. 79 



23. Head not constricted at the base behind the eyes 24 



Head constricted at the base and behind the eyes, swollen between; pronotum 



divided into three lobes; hemelytra wholly membranous, provided with 

 longitudinal veins and a few crossveins; front tibiie swollen; front tarsi 

 one-jointed, hind tarsi two-jointed. (Henicocephalus) (PI. 14, fig. 336). 



HENICOCEPHALID^ 



24. First joint of antennae longer than the second; hemelytra with submembra- 



naceous corium with elevated veins, the clavus and membrane membra- 

 naceous, confluent, the latter destitute of veins. (Mesovelia.) 



MESOVELIID^ 



First joint of antennre shorter than the second; hemelytra with distinct clavus, 



corium and membrane, the latter with four or five contiguous longitudinal 



cells; eyes large and projecting; small, flattened forms. Shore-bugs. i, 



(Acanthia {=SaId(i).) (PI. 13, fig. 315.) .... (SALDID^) ACANTHIID^ 



25. Antennse elbowed, filiform or often slender apically; membrane with two or 



three large basal cells 26 



Last joint of antennae knobbed or enlarged in the middle; membrane with the 

 veins joined, frequently forked and uniting; tarsi two-jointed; front legs 

 formed for grasping, the femora much thickened. (Phymata.) /--' 



{PHYMATlDyE) MACROCEPHALID^ 



26. Rather robust, predatory species, body not linear. Assassin bugs. (Melano- 



lestes [M. picipes. Kissing bug], Conorhinus [C. sanguisugus. Big Bedbug], X 



Sinea) (PI. 13, figs. 316, 193; PI. 14, fig. 338) REDUVIID^ 



Linear species with excessively long and thin legs. (Emesa.) . .EMESID.^ 



27. Head not shield-like, the margins usually obtuse; antennae completely visible 



from above 28 



Head more or less expanded, the side margins acute in front of the eyes; at 

 least the first joint of the antennae not visible from above; membrane with 

 several veins 36 



28. Antennae five-jointed, the second joint short; clavus membranous, largely 



confluent with the membrane which is destitute of veins; tarsi two-jointed. 



(Naeogeus.) {HEBRIDM) NiEOGEID^ 



Antennae four-jointed 29 



29. Ocelli absent 30 



Ocelli present 31 



30. Hemelytra of the fully winged forms consisting of clavus, corium and mem- 



brane; beak free; tarsi three- jointed; stout bugs of moderate size. (Dys- 



dercus [D. svturelhis. Cotton Stainer]) PYRRHOCORIDyE 



Hemelytra wholly membranous, densely reticulated; cheeks entirely raised, 

 forming a groove which includes the base of the beak; tarsi two- join ted; 

 flat bugs of small size. Lace-bugs, (Cor3rthuca [C. arcuata. Hawthorn 

 Lace-bug]) (PI. 14, fig. 340) TINGITIDiE 



31. Membrane with many longitudinal veins which often unite; antennae inserted 



well up on the sides of the head 32 



Membrane with at most five veins 34 



