No. 22.] HYMENOPTERA OF CONNECTICUT. 255 



99. Head transverse, cheeks usually not much swollen; abdomen 



sessile or subsessile 100 



Head more or less cubical, spherical or subquadrate, more 

 or less extended behind eyes, mandibles generally pro- 

 truding and forming with the depressed mouth a kind of 

 mouth opening; abdomen sessile or subsessile, rarely petio- 

 late 115 



100. Abdomen subcompressed (but never so that its dorsum be- 



comes carinate), and always broader than high or de- 

 pressed at base; ovipositor issuing from apex of abdomen, 



last ventral segment long, lanceolate 101 



Abdomen distinctly broader than high or depressed, some- 

 times subcompressed toward apex in female 102 



101. Areolet triangular, petiolate, receiving second recurrent vein 



at or near its tip; legs and antennae slender; clypeus with a 

 suture between it and the rest of the face. . Coleocentrus p. 327 

 Areolet wanting; hind tibiae and tarsi long and slender, tibiae 

 almost twice the length of hind femora, which latter are 

 somewhat thickened; antennae much longer than head and 

 thorax; first submarginal cell receiving both recurrent 

 veins, or second recurrent vein uniting with transverse 

 cubital vein Arotes p. 326 



102. Dorsulum transversely rugose; fore tarsi more than twice 



as long as fore tibiae 103 



Dorsulum not transversely rugose; fore tarsi not twice as 

 long as fore tibiae 104 



103. Hind coxae not cylindrical, but swollen towards base; abdo- 



men finely sculptured, convex above in male, with sub- 

 quadrate segments that are neither emarginate at apex 



nor channeled Rhyssa p. 326 



Hind coxae cylindrical; abdomen smooth and shining, very 

 much longer than wide in male, flat above, and with 

 third to seventh dorsal abdominal segments more or less 



grooved longitudinally and emarginate at apex 



Megarhyssa p. 324 



104. Second and succeeding dorsal abdominal segments with their 



surface uneven on account of presence of tubercles or de- 

 pressions, or both, or even and without tubercles, but with 



body yellowish 105 



Second and succeeding dorsal abdominal segments even and 

 without tubercles or depressions, but body not yellowish 111 



105. Intermediate segments of abdomen, at least in male, longer 



than broad, rarely quadrate 106 



Intermediate segments of abdomen invariably broader than 

 long; fore femora not emarginate 107 



106. Areolet triangular; exserted portion of ovipositor as long as 



or longer than abdomen; tarsi with their apical joint three 



