NO. 2105. NEW SPECIES OF HYMENOPTERA—UOIIWER,. 211 



PTERONIDEA ACERIS, new species. 



Female. — Length 6.5 mm. Anterior margin of the iabrum trun- 

 cate; clypeus short, not strongly convex, anterior margin broadly, 

 arcuately emarginate, the lobes low, obtusely rounded apically and 

 about half the width of the emargination in width; supraclypeal area 

 strongly convex; middle fovea deep, almost circular in outline; 

 frontal crest but slightly broken; antemial furrows complete above 

 the crest; crest sharp; the lateral dorsal walls of the postocellar basin 

 obsolete, the lower walls well defined, sharp, indicating a pentagonal 

 ocellar basin; a small, shining fovea directly in front of anterior 

 ocellus; postocellar line subequal in length with the ocellocular line; 

 postocellar area not well defined laterally; the lateral furrows indi- 

 cated only anteriorly and originating immediately behind the lateral 

 margin of the lateral ocelli; antennae antenniform, the third and 

 fourth joints subequal; thorax shining, impunctate except the setig- 

 erous punctures; stigma angulate slightly basad of the middle, taper- 

 ing to the apex, broad; second recurrent and second transverse 

 cubitus interstitial; third cubital cell slightly widening apically, 

 about half as long as its apical width; discal cells of the hind wings 

 of equal length; teeth of the claws subequal in length; sheath stout, 

 straight, above, tapering from an obtusely rounded apex to a broad 

 base. Black; Iabrum, mandibles, except apices, clypeus, supra- 

 clypeal and lateral supraclypeal areas, spot on the inner posterior 

 orbits, pronotum, tegula, spot on the scutellum, line on the scutellum, 

 spot on the mesepisternum dorsally, and abdomen except infuscate 

 basal plates, ferruginous; antennae brown, slightly paler beneath; 

 legs except apical joints of the four anterior tarsi, apices of the pos- 

 terior tibiae and the entire posterior tarsi which are infuscate, pallid; 

 wings hyaline, slightly iridescent, venation dark brown. 



Charter Oak, Pennsylvania. Described from one female recorded 

 under Bureau of Entomology Number Hopk. U. S. 10708<?. Material 

 collected by T. E. Snyder and reared June 15, 1913, bv S. A. Rohwer. 



Type.—Csit. No. 18190, U.S.N.M. 



This species is related to populi and hudsonica Dyar. The follow- 

 ing table will separate it and the other species which fall in the cate- 

 gory entitled "Angles, etc., pale," on page 45 of Marlatt's Revision 

 of the North American Nematinae. 



Clypeus, supraclypeal area black (antennal furrows not depressed sharply above the 



crest) pulchella Rohwer 



Clypeus and supraclypeal area pale 1 



1. Lateral wall of the ocellai- basin obsolete; second recurrent and second transverse 



cubitus interstitial aceris Rohwer 



Lateral wall of the ocellar basin well defined; second recurrent an tif ureal 2 



2. Lateral lobes of mesoscutum mostly black, basal segments infuscated. 



populi Marlatt 

 Lateral lobes of the mesoscutum reddish, basal segments pale. 



hudsonil-magnus Dyar 



