Female, length 9mm. Head yellow; vertex, a wide stripe from vertex to mouth, widened at antennae and spreading out on the cheeks in the region of the mouth, antennae and occiput, black; eyes hairy. Thorax shining; apical two-thirds of scutellum including the spines, an irregular spot each side between the scutellum and base of the wing, four longitudinal lines abbreviated behind, a triangular spot before the base of the wing, and two spots beneath it, bright yellow. There is also a minute yellow spot on each side of the thorax posterior to the lower corner of the eye, the yellow markings on the disc of the thorax extend for one-fifth of their length behind the transverse suture, while those on the sides extend from the humerus to the transverse suture. The femora except at base and apex are black, and the last three tarsal joints are brown, remaining parts of the legs are yellow; wings hyaline, veins dull yellow, halteres bright yellow. Abdomen black; a spot under the scutellum, a spot each side on the lateral part of the second segment, an elongate oblique band nearly meeting its fellow of the opposite side of each of the third and fourth segments, and apex, yellow. On the venter the hind margins of the third and fourth segments are yellow for their entire width, nearly the whole of the middle part of the second segment and a narrow band on the posterior margin of the first segment are also yellow. The lateral margins of the segments of the abdomen are black between the yellow markings, and there is no connection between the yellow markings on the abdomen. A female specimen taken by E. J. Oslar at Boulder, Colorado, August 19, 1899. In many respects this species agrees with Osten Sacken’s _decem-maculatus_, but it cannot be that species as the markings are very different. Aside from the hairy eyes it appears to belong to _Euparyphus_. The third joint of the antennae is composed of six rings with the last ring the longest. The fifth posterior cell meets the discal and its general form agrees very closely with _bellus_ and _tetraspilus_. AKRONIA n. gen. (Fig. 1.) [Illustration: Fig. 1. ] Head conically produced. Front in the female noticeably wider than the eye, in the male about half as wide as in the female. Antennae three-jointed, first and second joints about equal in length, third much longer than the other two together and composed of six rings. Posterior orbits wide in both sexes, but widest in the female, scutellum without spines, four posterior veins arising from the discal cell, abdomen short and broad, nearly circular in outline. Named for Akron, Ohio, in which vicinity I have procured many rare species. AKRONIA FRONTOSA n. sp.