No. 22.] HYMENOPTERA OF CONNECTICUT. 



439 



latter is shorter than the third, which in turn becomes slightly 

 thicker toward its apex, fourth to sixth joints about the same 

 in size and shorter than the third, the remaining joints somewhat 

 smaller but uniform in size, apical joint rosebud-shaped, antennae 

 sparingly covered with yellowish hair; thorax smooth and shin- 

 ing, parapsidal grooves present, scutel less shining than the rest 

 of the thorax and deeply corrugated in much the same manner 

 as the sides and extreme anterior portion of the thorax ; legs 

 testaceous. 



The galls of this species occur on the stems of wild dew- 

 berry, Rubus villosus {canadensis). New Haven, 9 May, 1907 

 (B. H. W.). 



D. niger Bassett. 



Female : length 2 mm. ; entirely black and shining ; head finely 

 punctate, antennas 13-jointed, first and second joints reddish 

 brown, all except the second of equal length ; thorax smooth and 

 shining, dorsulum with only the parapsidal grooves present and 

 bounded behind by a sharp transverse ridge, scutel rugose, hardly 

 bifoveate though there is a scarcely discernible line dividing the 

 large shining basal pit; legs brown; wings hyaline, veins dark, 

 first and second transverse veins distinct, radial area open and 

 with a dark cloud at its base, areolet wanting, cubitus distinct 

 and thickest where it joins the first transverse vein ; abdomen 

 shining black, the sheath of the ovipositor translucent brown. 



The galls occur on Potentilla canadensis, differ greatly in 

 form and size, the smallest being round or oval and not larger 

 than the smallest pepper seed, and containing not more than one 

 or two larval cells, the largest being 25 mm. long and 6 mm. in 

 diameter, involving the whole stem, and containing a dozen 

 or more larval cells. When the large galls include a joint of 

 the plant the former is enlarged with the rest of the plant but the 

 axillary buds are not affected. 



D. turgidus Bassett. 



Female : length 3 mm. ; head black and shining, antennas red- 

 dish brown, 13-jointed, the joints nearly equal in length, the 

 upper portion of the face roughened, the lower portion with fine 

 grooves converging toward the mouth ; mesothorax smooth and 

 shining black, parapsidal grooves present, the lines between the 

 latter to be seen only in a favorable light, faint linear depres- 



