No. 22.] HYMENOPTERA OF CONNECTICUT. 21/ 



Clypeus emarginate so as to form a semicircular opening 

 with mandibles, occiput separated from vertex by a ridge 

 or raised line; abdomen sessile or subsessile 24 



2. Abdomen above with more than two sutures, sutures distinct 3 

 Abdomen above without a suture or at most with two super- 

 ficial sutures, concave beneath 19 



3. Second submarginal cell large, quadrangular, or wanting. . 4 

 Second submarginal cell small, minute, often imperfect; 



notauli distinct; marginal cell not reaching apex of wing 16 



4. Abdomen sessile or subsessile 5 



Abdomen petiolate 13 



5. Fore wings with three submarginal cells 6 



Fore wings with two submarginal cells ll 



6. Anterior margin of marginal cell longer than stigma, mar- 



ginal and second and third submarginal cells distinctly 



defined 7 



Anterior margin of marginal cell not longer than stigma .... 10 



7. Hind femora thickened, sometimes toothed; head subquad- 



rate, vertex excavate, its fovea harboring the middle ocel- 

 lus 8 



Hind femora simple; head transverse, vertex not or scarcely 

 excavate; middle ocellus not harbored by a fovea; abdo- 

 men linear, longer than thorax, inserted above hind coxae 



Macrocentrus p. 219 



8. Hind femora unarmed 9 



Hind femora armed with a tooth beneath Helconidea p. 220 



9. Basal joint of hind tarsi not longer than second, third, and 



fourth joints combined Helcon p. 220 



Basal joint of hind tarsi longer than second, third, and fourth 



joints combined Eumacrocentrus p. 220 



ID. First branch of marginal vein shorter than second; sec- 

 ond submarginal cell longer than first Ichneutes p. 221 



First branch of marginal vein hardly longer than second; sec- 

 ond submarginal cell shorter than first .... Ichneutidea p. 221 



11. Anal cell of fore wings open at apex; marginal vein straight, 



its first branch long and distinct; ovipositor straight; first 

 discoidal cell sessile, touching parastigma; cubital vein 



arising from base of stigma Blacus p. 222 



Third discoidal cell of fore wings closed at apex 12 



12. Abdomen elongate, its sides parallel, showing eight segments 



above, the first much longer than broad Eubadizon p. 221 



Abdomen short, sides rounded, showing at most only three 

 or four segments above, the rest retracted, first seg- 

 ment not or scarcely longer than its apical breadth 



Brachistes p. 221 



13. Fore wings with two submarginal cells or without submar- 



ginal cells 14 



Fore wings with three submarginal cells Meteonis p. 222 



