No. 22.] HYMENOPTERA OF CONNECTICUT. 53I 



Labial palpi with three joints BELYTIDJE p. 568 



11. Labial palpi with two joints, hind wings with no basal cell 



DIAPRIIDyE p. 561 

 Labial palpi with three joints, hind wings always with a 

 basal cell BELYTID^ p. 568 



12. Mandibles without teeth, antennae with thirteen joints 



SERPHID^ p. 573 

 Mandibles with teeth, antennae with fourteen or fifteen joints 



HELORID^ p. 576 



PLATYGASTRID^. 



The species of this family are parasites of the larvae of gall- 

 gnats or midges and crane-flies, etc. 



Key to Genera. 



1. Submarginal vein in front wings ending in a stigma or knob; 



tarsi 5-jointed, antennae lo-jointed, front wings without a 



basal nervure 2 



Submarginal vein entirely absent or indicated only at base, 

 never knobbed 3 



2. Lateral ocelli nearer to eye margin than to front ocellus, 



basal segment of abdomen with a horn above 



Inostemma p. 532 

 Lateral ocelli nearer to front ocellus than to eye margin 



Isostasius p. 532 



3. Scutellum lengthened, not semicircular; if shortened, com- 



pressed at sides and furnished with a spine 4 



Scutellum not lengthened, semicircular, always unarmed.... 5 



4. Abdomen much lengthened; club of female antennae 5-jointed 



Polymccus p. 534 

 Abdomen not especially lengthened; club of female antennae 

 4-jointed; scutellum with a thorn, or sometimes only a 

 tubercle; lateral ocelli nearer to eye margin than to front 



ocellus; mesonotal furrows sometimes present 



Amblyaspis (includes Leptacis and Synopeas)*p. 532 



5. Scutellum flat or subconvex 6 



Scutellum convex or cushion-shaped 7 



6. Mesonotum without furrows; antennae lo-jointed, with a 



jointed club in female Anopedius p. 533 



Mesonotum with more or less distinct furrows; antennae 

 8-jointed in female, with an unjointed club Amitus p. 534 



7. Scutellum bare 8 



Scutellum with a tuft of hairs at tip; lateral ocelli not close 



to eye margin; club of antennae 5-jointed Trichasis p. 534 



8. Abdomen of usual length 9 



Abdomen much lengthened Polymecus p. 534 



* These genera are all included together, as they do not appear to be separable by any 

 trustworthy characters. 



