H. F. BASSETT. 335 



Win (HdiiN fragilis n. sp. 



Galls. — They resemble in form and structure the galls of N. 

 irregularis 0. S. and N. majalis Bass., but are much smaller and of 

 greater density than either of these species. They are a pale yel- 

 lowish white and occur on the leaves of a small oak in southern 

 California, probably Q. wrens or a related species. The galls are 

 polythalamous, but even the largest contain very few individuals. 



Gall-fly. Male and female.— Color pale trauslucent brown, except the minute 

 abdomen which is dusky brown. Abdomen very long, pedicellate, the remain- 

 ing segments forming a minute, equilateral triangle. Legs very pale and slen- 

 der. Wings subhyaline; veins very distinct but small. A reolet present. Radial 

 area open. Antennae of the eight males in my collection all broken at the first 

 or second joint. The female antennae has fourteen joints, the first small and 

 short, second relatively very large, the following very short. Body .05, wings .08. 



A very minute species and differing materially from all others of 

 this genus known to me. 



Collected at or near San Diego, Cal., by Mrs. D. B. Hamilton. 



IVeuroterus cousimilis n. sp. 



Gall. — Leafy and greatly foreshortened and enlarged branchlets 

 of the white oak. Of solid, woody texture, polythalamous, one-half 

 an inch thick (dry specimens), and three-fourths of an inch long. 

 They mature in mid-Summer. 



Gall-fly. Male. — Head shining black, broader than the thorax. Antennae fif- 

 teen jointed, longer than the body, first and second joiuts short, the second glo- 

 bose, those following nearly equal in length, dull dusky brown. Thorax and 

 scutellum dull black, microscopically punctate. Parapsides reduced to two brief 

 divergent lines beginning on the scutellum. Groove separating the mesonotum 

 from the scutellum broad and shining in the middle, but no distinct fova?. Scu- 

 tellum small. Abdomen extremely small, very black. Legs— posterior pair 

 dark, nearly black, except at the joints, middle and the anterior pairs a uniform 

 dull yellowish brown. Wings hyaline; veins very dark and well defined. Areo- 

 let small. Eadial area open. Body .06, antennas .08, wings .08. 



Female. — Body black. Antennas in my four specimens are broken. The basal 

 joints, which still remain, darker than those of the male. Thorax — parapsides 

 wanting. Fovse absent, but the transverse groove rather broad and smooth. 

 Abdomen black, large, the terminal segments retracted within the first, which is 

 vertically very wide or deep. The posterior pair of legs are even darker than 

 those of the male. Wings same as the male. Body .08, antennas .07, wings .09 



Four females, two males. Waterbury, Conn. 



NeuroteniM dubia n. sp. 



This species was found in a box of galls of A. prionosus, but no 

 galls appear from which they seem to have come. Both sexes. 



TRANS. AM. ENT. SOC, XXVI. JULY 1900. 



