588 FAMILY XX. — NABID^E. 



either entire and covering the abdomen or abbreviated and 

 usually not reaching its middle, when entire with clavus and 

 corium submembranous and membrane large and furnished 

 with four long veins which near apex give rise to several short 

 ones ; front legs raptorial, the tibiae armed with setae or minute 

 spines and in repose fitting closely against the swollen femora ; 

 tarsi 3-jointed, their claws terminal. 



The family is of small size, only 21 species being known from 

 America north of Mexico. They are predaceous in habits and 

 occur for the most part on the foliage and flowers of herbs 

 growing in dense woods or along the margins of ponds, lakes 

 and streams. Here they wander about in search of plant lice 

 and soft bodied larvae and nymphs of other plant-feeding in- 

 sects. They are therefore to be classed as beneficial, though 

 their numbers are too few to be of great value. Our eastern 

 species are distributed among two subfamilies. For literature 

 pertaining to them see Stal, 1873 ; Reuter, 1873, 1873a, 1890, 

 1908; Champion, 1899; Parshley, 1920, 1923. 



KEY TO EASTERN SUBFAMILIES OF XABID.-E. 



a. Antennae 5-jointed, the second joint short; front lobe of pronotum 

 with subapical constriction wanting or very close to front margin, 

 the collar, therefore, very short; corium and clavus coriaceous, 

 opaque, the latter not widened behind. 



Subfamily I. Prostemmin^e, p. 588. 

 aa. Antennas 4-jointed, the second joint long; front lobe of pronotum 

 with subapical constriction placed some distance behind front 

 margin, the apical collar wide; corium and clavus submembranous 

 and subtranslucent, the clavus widened opposite apex of scutel- 

 lum. Subfamily II. Nabin,£, p. 590. 



Subfamily I. PROSTEMMINvE Reuter, 1890, 289. 



The members of this subfamily are so different in structure 

 and facies from our other Nabidae that they should be placed 

 in a family by themselves. Our eastern species have the head 

 immersed in thorax to eyes ; antennae distinctly 5-jointed, the 

 second joint only about one-fifth the length of third ; ocelli 

 very small, placed close to the inner basal margin of the eyes; 

 pronotum without a distinct collar, the postmedian constriction 

 vague; elytra in great part coriaceous, commissure shorter 

 than scutellum ; front femora strongly swollen, shallowly 

 grooved beneath, the inner margin of the groove beset with 

 numerous short stout black setae; front tibiae with apical fourth 



