339 



anterior margin, a broad one extending from lower margin almost 

 to upper margin between the former and the blue central stripe, and 

 a rather broad one along posterior margin. Thorax glossy black, the 

 disc very densely punctate, so that it appears less glossy than the sides; 

 center of disc with a narrow line of silvery pile which extends pos- 

 teriorly to the diagonal median sutures, the latter with similar silvery 

 pile ; sides of mesonotum with silvery pile which is arranged in short 

 irregular stripe-like groups anteriorly, and rather evenly on the entire 

 surface posteriorly ; scutellum without silvery pile. Abdomen slightly 

 shining, the surface with piliferous punctures, the hairs slender and 

 rather sparsely and regularly arranged. Legs yellowish white, coxae, 

 trochanters, and femora except their extreme apices, shining black. 

 Wings hyaline, veins pale yellow\ Halteres brown, knobs white. 



Frons about one fourth the width of head, distance from upper 

 extremity of lateral silvery stripe to anterior ocellus greater than its 

 width at former point ; antennae larger than in punctifer, third joint 

 higher than long; arista slender, hair-like; antennae inserted below 

 middle of eye, in profile. Scutellum more elongate and less abruptly 

 humped than in punctifer. Abdomen differing from that of punctifer 

 in the absence of the punctiform groups of silvery pile. 



Male. — Three male specimens which I have reared differ from the 

 female in having the eyes much closer above, the distance between 

 them not exceeding one tenth the width of head, the antennae smaller 

 and with the third joint conspicuously browned apically, and the eye 

 with only 2 vertical purple stripes — one along anterior margin and 

 the other just proximad of middle, the latter not extending to lower 

 margin. In other respects the sexes agree very closely. 



Length, 4 mm. 



Type from Savoy, 111., May 4, 191 6, larva under loose bark of 

 apple-tree; imago emerged June 17, 19 16. Paratypes from Urbana, 

 111., October 21, 1916, larvae under bark of felled elm-tree; imagines 

 emerged December 29, 19 16 and January 5, 1917. 



I have pleasure in dedicating this species to Mr. Samuel Hen- 

 shaw, of the Cambridge (Mass.) Museum of Zoology, who kindly 

 submitted the material in that collection for examination when I wrote 

 the paper containing the description of punctifer. 



There is a specimen of henslmzvi in the Cambridge collection about 

 the sex and identity of which I had some doubt when I examined it. 

 It agrees in every respect with the female now before me. 



It seems worth mentioning that while the eyes of both of the 

 above species have vertical color-stripes, Pachygaster piilcher has 4 



