THE CANADIAN ENTOMOLOGIST. 97 



Abdomen petiolate, small, smooth, shining and tai)ering to a rcjnc-like 

 point at each extremity. 



Length — body .08, wing .10, antennae .07. 



Female : Entire body excejit the antenme and legs apparently black, 

 but really a very dark brown. Antenna? 13-jointed, and as in the male, 

 except that they are shorter and the 3rd joint is straight. First segment 

 of the abdomen (petiole ?) short, remaining ones taken together not longer 

 than deep. 



"Fhe color, the much smaller wings (only .08), the shorter antenna; and 

 the very short petiole give to the female an appearance so distinct from 

 that of the male that it is not easy to believe that they belong to the same 

 species ; but that they are the same is proved by their being often found 

 ifi coitu^ and indirectly by the fact that there are several other species in 

 which the sexes differ in the same way, and to almost as great an extent as 

 in this case. 



Length — body .07, wing .08, antenna? .05. Not rare in this section. 



Cynips vesicula, n. sp. 



Gall a small, smooth, reddish brown vesicle developed from the centre 

 of the buds of Qiierats alba, surrounded at the base by the bud-scales. 

 The color is sometimes a pale greenish brown. The walls of the gall are 

 thin and the larva free, that is, having no larval cell. These galls are par- 

 tially developed in the preceding autumn, and mature so rapidly in the 

 spring that the insects emerge about the time the leaves of the oak begin 

 to expand. 



Gall fly — Male : Head small, black, vertex triangular, and nearly cov- 

 ered by the large and protruding ocelli which form an equilateral triangle. 

 Eyes very large. Face narrow, almost linear, the breadth considerably less 

 than half the width of one eye as seen from the front. Antennae long, 

 filiform, 15-jointed, I St and 2nd joints short, globular, 3rd deeply incised, 

 the remaining ones nearly equal in length, except the very short terminal 

 joint ; I St joint nearly black at the base, the others yellowish brown, darker 

 towards the ti]) of the antennse. Thorax shining black with extremely fine 

 microscopic reticulations ; no grooves or lines. Scutellum ; surface as the 

 mesothorax. Fov^e shallow and indistinct. Wings very large, clear smoky 

 brown. Veins dark and heavy, the 2nd transverse when the wings are 

 closed on a line with the extremity of the abdomen. Cubitus heavy and 

 reaching quite to the ist transverse. Areolet distinct. Radial area long 



