No. 22.] HYMENOPTERA OF CONNECTICUT. l8l 



vipionim:. 



Key to Genera. 



1. Clypeus not emarginate so as to form a semicircular open- 

 ing with mandibles 3 



Clypeus emarginate so as to form a semicircular opening 

 with mandibles; occiput without a ridge or raised line 

 between it and vertex, at most with a faint raised line 

 at sides 7 



2. Second submarginal cell large, quadrangular, or wanting; ab- 

 domen sessile or subsessile; fore wings with three sub- 

 marginal cells, anterior margin of marginal cell longer 

 than stigma 3 



Second submarginal cell small, often imperfect; mesothor- 

 acic sutures invisible; marginal cell reaching or nearly 

 reaching apex of wings; antennae less than 20-jointed; me- 

 dian cell shorter than submedian 4 



3. Marginal and second and third submarginal cells indistinctly 

 defined, marginal cell reaching to apex of wing; marginal 



vein indistinct beyond apex of second submarginal cell, 

 which is much longer than broad, the recurrent vein re- 

 ceived by first submarginal cell Cardiochiles p. 183 



Marginal and second and third submarginal cells distinctly 

 defined; hind femora simple; head transverse, vertex not 

 or scarcely excavate, middle ocellus not surrounded by a 

 fovea; abdomen ovate, not longer than thorax; occiput not 

 margined; anal cell of fore wings without a transverse 

 vein; marginal cell completely closed; second branch of 

 marginal vein much longer than first, whereby second 

 submarginal cell is wider, often very wide; marginal vein 

 not springing from extreme base of stigma; second and 

 third abdominal sutures inconspicuous Opius p. 182 



4. Antennae 18-jointed 5 



Antennae 14-jointed Mirax p. 184 



5. Fore wings with three submarginal cells, the second com- 

 plete 6 



Fore wings with two submarginal cells; second submarginal 

 cell fused with third, marginal vein obsolete or subobso- 

 lete Apanteles p. 184 



6. Spurs of hind tibiae half or more than half the length of hind 

 metattrsi Microgaster p. 201 



Spurs of hind tibiae less than half the length of hind meta- 

 tarsi Microplitis p. 202 



7- Abdomen without or with only one foveolate transverse im- 

 pression; clypeus without hair tufts at base; face not 

 rostriform 8 



