142 AV. H. ASHMEAD. 



\ 

 Gall fly.— ^. Length .08 inch. Color black, legs brownish yellow, antenna- 

 dusky. Head and thorax finely punctate; antenna- 13-jointed; abdomen pol- 

 islied black, ventral valve projectin.s, its tip pubescent ; wings hyaline, veins pale 

 yellowish. 



Described from two specimens taken out of galls in September, 

 1885, since which time I have failed to secure additional specimens. 



Galls 0)1 the Ujtlaml Willow or Blue Jack Oak (Quercus einerea). 



To the seven species, described by me, as occurring on this oak, I 

 add four new species: one a "Jumping Gall" of great interest, taking 

 one whole year to develop ; anothei' a minute gall found on the blos- 

 soms or aments ; and still another, Andrku.< difficilis, which has taken 

 me just six years to work up. 



24. Aiidrictis (Trisoleiiia n. g.) saliatii<!« n. sp.— (The Blue Jack 

 Jumping Gall.) 



Galls. — Obloug-oval, longitudinally ribbed, browu galls, without a distinct cell, 

 occurring two or three together and issuing froui the bud axils in early spring; 

 they are but slightly attached and fall to the ground ou the slightest jarring of 

 the tree. 



Gall-fly. — 9- Length .17 inch. Head and thorax dark l)rown-black, finely 

 rugoso-punctate, opaque; ocelli red, shining; antennse IG-jointed, as long as 

 thorax, pale brown; parapsidal grooves distinct, with a distinct median groove 

 between, some punctures along the edges and two short pai-allel grooves, one on 

 either side of median groove parallel with it, but only extending half way on 

 the mesothorax : between the parapsidal grooves and the groove extending from 

 base of wing is another short longitudinal groove ; scutellum coarsely reticu- 

 lately rugose, with two large, shallow, oblique, shining fovete at base; pleurse 

 striate in front, becoming rugose posteriorly ; legs reddish brown, the thighs and 

 outer edges of femora and tibiiB obfuscated, punctate and pubescent ; coxse, black, 

 smooth and shining above; beneath pubescent. Abdomen dark reddish brown, 

 shining, with a few hairs on sides of second segment. Wings hyaline, veins pale 

 brown, slightly yellowish, submarginal brown, stouter, radial area open, the 

 areolet very large, distinct, cubital cell only half closed. The % differs from 9 

 in having 17-jointed antennae and being almost entirely a pale reddish brown; 

 the femora and tibige are but slightly obfuscated. 



Described from several specimens. 



This gall was discovered three years ago ; it appears the last of 

 March, and when first taken from the tree and for several weeks 

 afterwards, has the power of jumping, due to the contractions and 

 sudden relaxation of the larva within ; some of them will jump three- 

 quarters of an inch off the table. Out of nearly two hundred galls 

 gathered the first year of its discovery, but one reached maturity ; 

 all the rest died. This specimen was just eleven months and some 

 davs in the gall. In 188.5 but three specimens were raised, one a 



