NORTH AMERICAN HYMKNOPTERA. Ql 



punctate, except a very narrow polished band on the margin of each. Legs l)lack, 

 shining and with a few scattered hairs. Wings dark, smoky brown, a very dark 

 brown cloud covers the areolet and the lower half of the radial area ; beyond 

 this and extending across the radial area and almost to the posterior margin is a 

 light, nearly colorless spot, and the anterior margin from the dark, broad, first 

 transverse vein to a short distance beyond the second transverse is of the same 

 light color, the tip of the wing beyond the light spot is of the same dark smoky 

 hue as below this spot ; the areolet well defined, but very small ; radial area open, 

 large and broad. Length : body, .27 inch. ; wings, .24 inch. ; antenna;, .13 inch. 



NEITROTERUS Hartig. 

 1. ]V. Favostis u. sp. 



Flattened, polythalamous galls on the leaves of Quercus tinctoria 

 varying in latei'al diameter from one-fourth to almost an inch ; they 

 project from both surfaces of the leaf, but more ])rominently from 

 the upper surface; their vertical diametei' is not more than one- 

 fourth of an inch. The upper and under surfaces, especially the 

 first, bear a very close resemblance to a honey-comb. This resem- 

 blance is more striking after the insects have left, when the u])per 

 surface is literally full of holes. In general appearance they resem- 

 ble the galls of iV^. laajalls Bass., but when green they are less suc- 

 culent, and when dry they are of an extremely hard, ligneous tex- 

 ture, while the others are soft and pith like. I collected old galls in 

 September, 1888, from a single oak tree in Rockport, Ohio. This 

 year my nephew, Charles Nichols, collected a large quantity from 

 the same tree, and from them I have reared a large number of gall- 

 flies. These are of both sexes, and are described as follows : 



Gall-flies. — Male. — Head broader than the thorax, black, shining; cheeks 

 with indistinct furrows; antennse fifteen jointed, first dark brown, second 

 lighter, and the remaining ones light yellowish brown ; the first and second 

 oblong oval, and nearly the same length ; the third slightly longer than both the 

 preceding, club-shaped and curved, but only slightly incised, remaining joints 

 of uniform length and but a little shorter than the third, the whole exceeding 

 by two or three joints the entire length of the body. Thorax black and shining, 

 liut a powerful magnifier reveals a finely and evenly crackled surface ; parapsidal 

 grooves apparent posteriorly, but soon disappearing; by the deeply incurved pos- 

 terior margin of the mesothorax the scutellum has a rounded outline; furrow of 

 moderate depth and fovese subobsolete: surface of the scutellum same as the 

 mesothorax. Abdomen small, black and shining, second segment in dry speci- 

 mens almost concealing the remaining ones, but in the living insect the terminal 

 ones are visible and form a cone-like termination to the abdomen. Legs light 

 brown, somewhat darker in the middle of the femur and tibia: claws simple. 

 Wings of moderate size, hyaline, but when in a certain light they show a faint 

 steel-blue reflection ; this is more noticeable where several hundred specimens 

 are seen together; veins slender, brown, fading to colorless lines; areolet want- 

 ing. Length: body, .05 inch. ; wings, .05 inch.; antenna^, .06 inch. 



Female. — Head pale brown, shading to black on the posterior margin of the 

 vertex; antennae shorter than the body, pale yellowish brown, growing dusky 



