SUBFAMILY II. — NABIN^. 591 



bb. Ocelli separated by less than their own diameters; first joint of 

 antenna? more than twice the length of head; second joint of beak 

 much longer than third. II. Metatropiphorus, p. 604. 



I. Nabis Latreille, 1807, 127. 



A large genus of elongate or oblong-oval, usually slender- 

 bodied species having the pronotum campanulate with two fine 

 transverse constrictions, its sides gradually converging from 

 the posterior constriction to apex, humeral angles rounded, 

 hind margin subtruncate ; scutellum small, triangular, usually 

 in great part black, with a calloused yellowish spot each side, 

 its apex obtuse ; clavus widened behind ; elytra either entire 

 and reaching or surpassing tip of abdomen, or abbreviated and 

 usually reaching only second dorsal, when entire the membrane 

 with three elongate cells, their terminal bounding vein with 

 numerous short ones radiating to tip of membrane ; connexivum 

 in males of macropterous forms usually narrowly or not at all 

 exposed, in females more broadly so ; front femora spindle- 

 shaped, moderately swollen, both they and tibiae beset beneath 

 with numerous fine setae; front and middle tibiae with a short 

 spongy lobe at tip ; tarsi 3-jointed. More than 40 species are 

 known, 19 of which occur in this country, 17 of them from the 

 eastern states. Most of our species have in the past been 

 described or recorded under the generic name Coriscus Schrank. 



KEY TO EASTERN SPECIES OF NABIS. 



a. Body in great part shining black; sides of head behind eyes grad- 

 ually converging obliquely backward. • 564. subcoleoptratus. 

 aa. Body wholly or in great part gray, grayish-yellow or pale brown; 

 sides of head behind eyes parallel or nearly so. 

 b. Front or middle femora, usually both, armed beneath with several 

 short black spines in addition to numerous setae; connexivum 

 usually with pale and dark spots. 

 c. Body short, broad, robust ; front femora strongly swollen ; abdo- 

 men beneath black; outer basal angle of each connexival with 

 a large black spot. 565. crassipes. 



cc. Body elongate, narrow; front femora only moderately swollen; 

 outer basal angles of connexivals with small dark spots or none. 

 d. Hind lobe of pronotum almost smooth; body not much constricted 

 at base of abdomen ; tibia? with five or more dark rings. 

 e. Sides of pronotum straight and rather strongly divergent from 

 apex to base; elytra, brachypterous form, obovate, the tips 

 broadly rounded and membrane scarcely evident; abdomen 

 beneath wholly fuscous. 566. nigriventris. 



