SUBFAMILY I. — LYG^EIN^. 339 



ff. Front femora less swollen, armed beneath with a single tooth; 

 corium expanded, extended over sides of abdomen, its outer 

 vein subparallel with its margin; hind coxae widely separated; 

 bucculse extended to base of head. 



Subfamily VI. Oxycarenin^e, p. 383. 



aa. Suture between the third and fourth ventrals (except in Plinthisus 



and Gastrodes) curved forward, not reaching the lateral margins 



(fig. 70) ; head usually with two setae near eyes; fore femora 



swollen and usually armed with teeth. 



Subfamily VII. Rhyparochromin,e, p. 384. 



Subfamily I. LYGiEINiE Stal, 1862a, 210. 



To this subfamily, as characterized in the key, belong the 

 largest of our Lygseids as well as some of moderate size. The 

 impunctate elytra, impressed sides of base of pronotum, slender 

 and usually unarmed fore femora and connected inner veins of 

 membrane serve well to distinguish them. In the tribe Orsillini 

 the females have ventrals 4 — 6 carinate, compressed and ap- 

 parently divided at middle, their apical halves triangular, 

 placed obliquely, with apices overlapping and converging to- 

 wards middle of third ventral, which is convex. The sub- 

 family is represented in the United States by six genera, five 

 of which occur in our territory. 



KEY TO EASTERN GENERA OF SUBFAMILY LYGiElNiE. 



a. Apical margin of corium straight, not sinuate inwardly; inner wings 

 wholly or in great part fuscous or inf uscated ; outer apical angles 

 of antenniferous tubercles obtuse; male with last dorsal segment 

 truncate and genital segment not foveate; color usually black 

 and red. (Tribe Lygseini Stal). 



b. Pronotum with base sinuate and disk with a nearly entire median 



carina ; scutellum convex, carinate toward apex. 



I. Oncopeltus, p. 340. 



bb. Pronotum with base truncate and disk without a median carina 



or with carina not reaching front margin; scutellum flat but with 



a more or less evident longitudinal carina usually joined to a 



transverse basal one. II. Lyg^eus, p. 341. 



aa. Apical margin of corium sinuate near clavus; inner wings subhya- 



line, not inf uscated ; outer apical angles of antenniferous tubercles 



acute or subacute; male with last dorsal rounded and genital 



foveate; color not black and red. (Tribe Orsillini Stal). 



c. Basal segment of antenna? equalling or surpassing tip of tylus; 



beak not surpassing first ventral; head of moderate length. 

 d. Costal margin of elytra straight throughout; eyes prominent, the 

 exposed area back of them greater than half their width; osteo- 

 lar duct ending in an external ear-like expansion. 



III. Ortholomus, p. 348. 



