No. 22.] HYMENOPTERA OF CONNECTICUT. I29 



at tip, slightly emarginate beneath, clothed with dark 

 brownish hairs; body black, with supraclypeal area, clyp- 

 eus, mouth-parts, pronotum, tegulae, pectus in great part, 

 legs except apices of hind femora and tibiae and hind tarsi, 

 and venter of abdomen, light resinous yellow; abdomen 

 at sides, and central area interrupted at base and apex, yellow. 



Length 6 mm carpini 



Mesonotum, at least in part, pale 22 



22. Median lobes of mesonotum in great part, and abdomen, 



black; frontal crest prominent, sometimes slightly broken; 

 median fovea shallow, indistinct; saw-guides obtusely 

 pointed, straight on upper edge, narrow; body ferruginous, 

 with head except palpi and clypeus sometimes in part, 

 margin of the pronotum, a band along middle of mesonotum, 

 metanotum, metapleuras, basal plates, abdomen above, 

 apices of posterior tibiae, and posterior tarsi, black. 



Length 7 mm militaris 



Median lobes of mesonotum and abdomen in great part red- 

 dish; ocellar basin with rounded walls; frontal crest un- 

 broken; median fovea shallow, circular; saw-guides rather 

 short and robust, regularly rounded at tip; body reddish 

 yellow, with antennae, head except tip of clypeus and more 

 or less of mouth-parts, scutellum more or less, metanotum, 

 center of basal dorsal area of abdomen, and saw-guides, 

 black. Length 6 mm thoracica 



23. Stigma and costa brown 24 



Stigma and costa yellowish hyaline 28 



24. Scutellum black 25 



Scutellum pale 27 



25. Frontal crest unbroken; ocellar basin with distinctly limit- 



ing walls; median fovea deep and triangular; saw-guides 

 short, rather robust, regularly tapering; body light green- 

 ish yellow, with antennae, large spot about the ocelli extending 

 onto the occiput, lobes of mesonotum, metanotum, large spot 

 on upper angles of pleurae, base of dorsal abdominal seg- 

 ments centrally, apex of saw-guides, apex of hind femora, 

 apical two-thirds of hind tibiae, and hind tarsi, black. 



Length 6 mm ostryae 



Frontal crest broad, slightly broken at middle 26 



26. Head nearly spherical when viewed laterally; clypeus rather 



narrowly and deeply emarginate; ocellar basin distinctly 

 defined, sides acute, finely raised; frontal crest broad, 

 somewhat broken at middle; median fovea broad, circular, 

 shallow; saw-guides narrow, rounded at apex; body pal- 

 lid or resinous, with antennae, spot on vertex, including the 

 ocelli and extending onto the occiput, mesonotum, metanotum, 



9 



