No. 22.] HYMENOPTERA OF CONNECTICUT. 427 



of the terminal joint, also with the median line on the thorax en- 

 tirely wanting ; the head less hairy but with a few scattered hairs 

 on the thorax and on the side of the second abdominal segment. 



The galls of this species are blister-like swellings in the 

 smooth bark of the roots of young white oak trees (Quei'cus 

 alba), completely covering the roots in some places for the dis- 

 tance of two feet or more from the tree. 



A. (C.) pulcher Bassett. 



Female : length 2 mm. ; head and thorax black, and evenly 

 punctate, except the scutellum, which is evenly rugose; antennae 

 1 4- jointed, the second oval, third one- fourth longer than the two 

 preceding taken together, remaining joints gradually shorter, all 

 connate, but alike distinct, and with a yellowish, almost metallic 

 hue, cheeks grooved; mesothorax rounded, median line a slight 

 depression, but punctate like the rest of the surface, parallel lines 

 rather broad, shallow and polished, parapsidal furrows very fine 

 and extending throughout, lines over the base of the wings 

 present but indistinct, scutel evenly rugose, foveae near together 

 and rather deep and ovally elongate ; legs very dark brown, claws 

 simple; wings hyaline, veins colorless, except the subcostal and 

 transverse, which are dark but not black, areolet wanting, radial 

 area open. Male; antennae 15-jointed, the first joint black, the 

 second ovate, the third longer than the first two and slightly 

 curved and incised, all except the first with the yellowish 

 metallic hue noticed in the female ; legs lighter than those of the 

 female, the posterior pair darkest ; the antennae somewhat longer 

 and the abdomen, smaller as usual in this sex. 



The galls of this species occur on the aments of Quercus tinc- 

 toria, also Q. rubra measuring when dry, shrunken and shriveled, 

 from 2.5 to 4 mm. in diameter. They are polythalamous, each gall 

 producing four or five insects. The interior of the gall is of a 

 very loose spongy texture and the outside thin and papery and 

 green like the leaves. When fresh they are round and of the 

 size of a common red currant. They differ from the galls of 

 Dryophanta palustris Osten Sacken, which are sonietimes found 

 on the aments of Quercus ilicifolia, in the thin and smooth 

 shell, and in being polythalamous. Flies of both sexes appear in 

 May. 



