832 AMERICAN HYMENOPTERA. 



lateral triangle. Legs a clear pale translucent brown at the joint, changing to 

 an almost glassy black in the middle of the femur and tibia. Wings hyaline, 

 veins dark, distinct, but not heavy. Eadial area long and narrow and open. 

 Areolet relatively large. Cubitus full length. Body .05, antennae". 05, wings .06. 



Visiting the same bush, June 10th, I found numerous galls in the 

 shape of an enlargement of the base of the young branches. In 

 some cases the galls hardly increased the size of the branch or inter- 

 fered with its growth ; in others it entirely checked its extension. 



The insects, which had been very numerous, had mostly left, but 

 from the galls I collected I bred at least a hundred flies— male and 

 female. The females do not differ in any material feature from 

 those taken ovipositing. 



Miih-. — Head, thorax and abdomen shining black. Antennae slender, fourteen 

 jointed, first and second short, third one-third longer than the first two, fourth 

 equal to one. and two together, fifth to thirteenth equal, fourteenth short. Color 

 a clearer shining brown than in the female antennae. 



From Waterbury, Conn. 



\<tiiol«'iiis |>e rill i ill 111 US n. sp. 



This is the smallest species from which I have ever reared any 

 gall-flies. They lie imbedded in the lamina of white oak leaves, 

 and show on both sides, but more distinctly on the upper side. 

 They are oval, pustule like bodies, only .04 long, .03 wide and .03 

 deep. I have only met them in a limited locality in Rockport, 

 ( Miio. In some cases two hundred can be counted on a single leaf 

 of ordinary size. Small as they are, they are so infested with para- 

 sites that comparatively few true gall-flies ever reach maturity. I 

 have reared a few of both sexes. The galls reach their growth 

 about June 25th, and the flies hatch out before July lDth. 



Female. — Head black. Antennas thirteen jointed, first and second joints rather 

 large, the rest short and dusky brown. Thorax very dark, almost black. No 

 parapsidal lines. Sen tell urn very small and somewhat rough. No fovas. Abdo- 

 men short and black. Legs translucent brown but paler at the joints. Wings 

 hyaline : veins small but distinct. Areolet very small. Radial area long, narrow 

 and open. 



Mate.— Head dark but not quite black. Antennas fourteen jointed. Thorax 

 highly polished and a fine dark brown. Abdomen very minute, slender, pedi- 

 celled and triangular and a reddish brown. Legs pale and almost glassy in 

 appearance. Body .03, antennae .03, wings .04. 



Note. — I have received within a week fresh galls of this species, 

 but the flies had nearly all escaped on their arrival, June 28, 1900. 



NeuroteriiM exiguissiiiiiis n. sp. 



Galls found in Autumn on the underside of leaves of (/. alba, 



