NORTH AMERICAN HYMENOPTERA. 143 



male, and the period of develo])nieiit was tlie same. This year all 

 my specimens seem to be dead, although I collected at different times 

 and endeavored as fi\r as possible to collect the most matured speci- 

 mens ; evidently the season was too dry f^^r them. Last March I 

 collected two females while ovipositing in the buds; the ovipositor 

 was so deeply immersed in the l)ud as to enable me to capture the 

 flies in my fingers before they had time to withdraw and escape ; 

 they agreed perfectly wdth the bred specimens. 



25. AiidriciiM diflicilis n. sp.— (The Difficult Gall.) 



Galls.— SmaW, irregularly rounded, densely rugose, grayish galls, slightly flat- 

 tened at sides, the rugosities arranged transversely in from five to six rows; 

 diameter through flattened sides .08 to .10 inch ; cro.ssways .12 to .15 inch ; height 

 .12 to .15 inch. These galls occur in clusters, issuing in rows from fissures or 

 slits in the terminal twigs; when mature they fall to the ground. 



Gall-fly.— 9 • Length .14 inch. Color reddish brown. Head finely punctate, 

 a dark brown streak on face, extending from base of antennae to clypeus ; eyes 

 and ocelli dark brown. Antennse 14-jointed, a little longer than head and thorax 

 together, yellowish brown, slightly infuscated at tips ; thorax almost smooth, 

 shining, with distinct parapsidal grooves, a median groove and a slight groove 

 near base of wings; pleurje dark brown, pubescent, the meso-pleurre showing 

 fine, short, microscopical strife; scutellum rugose not pubescent; legs uniform 

 yellowish brown, coxse. black; abdomen reddish brown, shining, showing its sur- 

 face, under a high-power lens, microscopically punctate, the second segment does 

 not occupy nearly one-half the length of abdomen with a few hairs at its sides, 

 the other segments are about equal in length ; wings hyaline, veins brown, the 

 radial area open, the radial vein undulated at tip', areolet distinct, cubital cell 

 almost closed, the cubitus ending just before reaching the first transverse ; there 

 is a slight yellowish cloud in the break in the second longitudinal vein, and 

 along the edge of the first transverse and second transverse veins. 



Described from four specimens. 



For six years I have been trying to rear the originators of this 

 gall and only succeeded this fall ; I have either collected the galls 

 too soon or too late. On my return tVom the mountains of North 

 Carolina, Se})tember loth, I found a few galls which still retained 

 flies, and from which the above descrii)tion is draAvn up. The flies 

 evidently escape from the galls by the last of August or early in 

 September. 



26. Aiidi'iciis blaMtoitliagiis n. sp.— (The Pollen-feeding Aiulricus.) 

 Galls. — Minute, smooth, oval galls the size of an entomological pin-head, oc- 

 curring on the aments or blossoms ; they are so small as to be easily mistaken for 

 the ovaries. 



Gall-fly. — Length .05 inch. Uniformly reddish brown, finely rugoso-jiunctate. 

 Antennse 13-jointed, they and legs pale yellowish bi'own. Abdomen reddish 

 brown, smooth and shining, slightly dusky towards ajiex ; wings hyaline, veins 

 pale, radial area open, areolet indistinct, cubitus ol)solete. 



