30 ENTOMOLOGICAL NEWS. [January, 



but in a few specimens the color is quite dark. Feet rufous and hairy, 

 with coxa; and tarsi more or less infuscate. Wings 5.5 mm long, areolet 

 large, radial nervure thickened at tip and not attaining the costa and the 

 cubital nervure not attaining the first transverse. 



Described from upwards of fifty specimens, all females, reared 

 from galls taken at Manitou, Col., Sept. 30, 1892. The flies 

 began to emerge from the galls October 20th, 



H. monticola n. sp. 



Galls. — Dense cellular growths, rather cylindrical in form, but 

 a little smaller at the base than at the free end and somewhat 

 compressed laterally, the diameter in the direction of the twig 

 being somewhat greater than the transverse diameter. The free 

 end is usually rounded, but may be flat, slightly compressed or 

 with a blunt elevated point. They are attached by a broad base 

 in cup-like expansions of the small twigs. The largest galls will 

 measure one-fourth of an inch in greatest diameter by the same 

 in hight. They are black and dirty on the outer end on account 

 of the accumulation of the dirt in the sweet substance which they 

 secrete during growth. They are of a yellowish or greenish 

 brown at the sides, the color being quite light at the base of the 

 galls. A few of the two or three hundred galls that I have are 

 reddish in color at the sides. Although the outer substance of 

 the galls is Y^i'Y dense, the central cell is easily separated from 

 it, and it seems large in proportion to the size of the gall. 



The galls are exceedingly abundant on scrub oaks at Manitou, 

 Col., and the galls are much visited by w^asps and honey bees 

 for the sweet which they secrete. 



Gall-fly. — Black, tinged with rufous on head, thorax and legs. Length 

 3.5 — 4 mm. Head small, face rugose, somewhat striate betjveen the eyes 

 and mouth, sparsely haired, vertex finely rugose, ocelli inconspicuous and 

 surrounded by a black area; antenna? black, 13-jointed, third joint a little 

 longer than the first and second together, fourth joint about equal to the 

 third, terminal joint as long as the two preceding, and all joints rather 

 sparsely haired for Holcaspis. Thorax rather coarsely punctured, the 

 punctures giving rise to hairs that form a sparse pubescence; parapsidal 

 grooves distinct, but narrow, and only reaching about one-half of the dis- 

 tance from the scutellum to the prothorax. The two parallel lines from 

 the collar and the lines over the base of the wings are very distinct; scu- 

 tellum broadly rounded posteriorly and with a shallow groove at base. 

 Abdofnen black, polished, second segment with fine gray pubescence on 

 either side near the base. Wings 5 mm. long, hyaline, nervures slender, 

 areolet large. Feet blackish, tinged with rufous, often appearing quite 

 ufous if held in the proper light, moderately pubescent. 



