No. 22.] HYMENOPTERA OF CONNECTICUT. IO9 



ing costa and stigma, pale ; body impunctate, pentagonal area 

 distinct, not strongly marked ; antennal segments three to five 

 sub-equal ; clypeus emarginate. Length 5 mm. 



Platycampus Schiodte. 



°P. americanus (Marlatt). Camponiscus americanus Marlatt. 

 Body rufous, with the antennas above, spot about ocelli, tip of 

 scutellum, postscutellum, metathorax more or less, hind coxae, 

 base of abdomen beneath, mesopleurse more or less, femora more 

 or less, apex of hind tibiae, and hind tarsi, brownish or infus- 

 cated; pentagonal area sharply defined; frontal ridge strong, un- 

 broken; median fovea broad and deep; antennal segments 

 three and four subequal. Length 5-6 mm. Larva feeds on 

 poplar. 



Priophorus Latreille. 

 Key to Species. 



1. Frontal crest never large and prominent and never extending 



laterally to eyes; entire free part of Sci always distinct. ... 2 

 Frontal crest large and prominent, extending laterally to 

 eyes; free part of Sci almost entirely atrophied; body 

 black, with legs beyond knees semi-resinous to brown; 

 clypeus transverse, deeply emarginate; antennal furrow 

 extending as a groove along lateral margin of antenna to 

 about the middle of the front, where it is interrupted by the 

 frontal crest, then continued as a short groove behind the 

 lateral ocelli; median fovea triangular, flat. Length 6 mm. 



simplicicornis 



2. Frontal crest distinct or subdistinct; color black, with apical 



half of legs paler 3 



Frontal crest wanting; ocellar furrow distinct; body resinous, 

 with head except mouth, antennae except two basal seg- 

 ments, and mesonotum and metanotum, black; clypeus 

 shallowly emarginate with rounded lateral angles; antennal 

 furrow continuous; median fovea shallow and indefinite; 

 pentagonal area wanting; third antennal segment longer 

 than fourth. Length 4 mm acericaulis 



3. Frontal crest broken by median fovea; sides of ocellar basin 



scarcely indicated; ocellar furrow distinct; body black, 

 with legs beyond knees, four hind trochanters, and anterior 

 femora on the sides, white ; clypeus transverse and deeply 

 emarginate; median fovea deeply concave; third and fourth 

 antennal segments subequal. Length 6 mm sequalis 



