No. 22.] HYMENOPTERA OF CONNECTICUT. 23 



Abdominal segments not strongly differentiated as petiole 

 and gaster 3 



3. Mesothorax anteriorly without the free prepectus shown in 



illustration of Chalcidoidea (Fig. 12) 4 



Mesothorax anteriorly with a prepectus as shown in Fig. 12; 

 usually winged, with venation reduced to a minimum as in 

 Fig. 11; usually less than 3 mm. in length and metallic ... 



CHALCIDOIDEA p. 443 



4. Tegulae present, wings usually well developed, sometimes 



vestigial or lost 5 



Tegulae wanting, wings entirely absent, habitus respectively 

 as in winged forms 9 



5. Pronotum with its hind angles or tubercles tangent to a vertical 



line drawn tangent to anterior edge of tegulae, touching or 



underlying tegulae 6 



Pronotum with its hind angles or tubercles always distinctly 



remote from tegulae 12 



6. Body not flea-like 7 



Body flea-like; trochanters usually composed of a single joint; 

 wings usually with a characteristic venation as shown in 

 Fig. 10 CYNIPOIDEA p. 361 



7. Wings with at least basal, median and submedian veins present, 



usually with venation well developed as shown in Fig. 8. . 8 

 Wings usually without veins or with only subcosta and part of 

 radius present, rarely as in Fig. 13 or as in figure of 

 Pelecinus in Packard's Guide SERPHOIDEA p. 529 



8. Trochanters composed of two joints ICHNEUMONOIDEA p. 176 

 Trochanters composed of one joint 14 



9. Body not flea-like, not compressed 10 



Body flea-like, compressed as in winged forms CYNIPOIDEA p. 361 



10. Body not densely hairy 1 1 



Body densely hairy VESPOIDEA p. 606 



11. First abdominal segment elbowed . . ICHNEUMONOIDEA p. 176 

 First abdominal segment not elbowed . . . SERPHOIDEA p. 529 



12. Hairs of dorsulum simple, not branched or plumose 13 



Hairs of dorsulum branched or plumose APOIDEA p. 698 



13. Abdomen with more than three segments visible, segments be- 



yond third not hidden SPHECOIDEA p. 645 



Abdomen with three segments visible, segments beyond third 

 hidden CHRYSIDOIDEA p. 602 



14. Cutting edge of mandibles turned inward, their tips meeting 



or overlapping when mandibles are flexed toward mouth 



VESPOIDEA p. 606 

 Cutting edge of mandibles turned outward, their tips usually 

 neither meeting nor overlapping when mandibles are flexed 

 toward mouth ICHNEUMONOIDEA p. 176 



