No. 22.] HYMENOPTERA OF CONNECTICUT. 219 



24. Fore wings with three submarginal cells; head not cubical, 



more or less narrowed behind eyes 25 



Fore wings with two submarginal cells; head cubical, or out- 

 side line of temples virtually in same plane as outside line 

 of eyes; sutures between dorsal abdominal segments dis- 

 tinct 27 



25. Subdiscoidal vein not interstitial with anal vein, originating 



below middle of discoidal vein; abdomen sessile, almost 

 always rugose, except apex, small smooth impressions 

 visible on second and third dorsal segments; ovipositor 



short or concealed 26 



Subdiscoidal vein interstitial with anal vein, or originating 

 above middle of discoidal vein; median and submedian cells 

 of equal length or nearly of equal length on median vein; 

 antennae more than 12-jointed and much longer than head 

 and thorax; suture between second and third segments 

 superficial; recurrent vein received by second submarginal 

 cell, which is much narrowed at base Hormius p. 236 



26. Suture between second and third segment obsolete; second 



submarginal cell trapezoidal; abdomen not longer than 

 head and thorax, in female subcompressed at apex, oviposi- 

 tor considerably exserted Epirhyssalus p. 235 



Suture between second and third segment distinct, crenu- 

 late; third joint of maxillary palpi not dilated, but 

 simple; recurrent vein received by first submarginal cell; 

 first branch of marginal vein shorter than second; sec- 

 ond submarginal cell elongate, more than half length of 

 first; fourth and following abdominal segments in female 

 not retracted and concealed beneath third. .. .Aleiodes p. 235 



27. First and second submarginal cells distinct, not confluent; 



marginal cell closed 28 



First and second submarginal cells confluent; abdomen above 

 showing more than three segments; hind wings with a 

 stigma Heterospilus p. 238 



28. Abdomen sessile, with only four segments visible above; 



ovipositor hardly exserted; recurrent vein received by 



first submarginal cell, hind wings without a stigma 



Polystenidea p. 238 

 Abdomen sessile, with at least six segments visible above; 

 ovipositor elongate; recurrent vein interstitial; hind wings 

 with a stigma Hecabolus p. 2yj 



Macrocentrus Curtis. 

 Key to Species. 



I. Species uniformly stramineous. Length 6-8 mm 2 



Head and thorax mostly black; antennae brown, except first 

 and second joints, which, like legs and venter of abdo- 



