Female. Length 4 lines.-Black: the head a little wider than the thorax, emarginate behind, with the lateral angles rounded and longitudinally rugose, rather finely so; the mandibles, anterior margin of the head, the carinae between the antennae, the base and apex of the scape, and also the tip of the flagellum, ferruginous. Thorax oblong-ovate; the metathorax obliquely truncate, the truncation transversely striated; the disk of the thorax longitudinally and finely rugose, the prothorax transversely so; the wings fusco-hyaline, the nervures testaceous; the tibiae and tarsi obscurely fusco-ferruginous. Abdomen oblong-ovate, thinly covered with a yellowish downy pile intermixed with a few long hairs, particularly at the apex; the node of the peduncle incrassate, of equal thickness at the base and apex, the superior margin rounded and elevated to the same height as the first segment.
Male. Length 3 lines.-Differs from the female in the usual characteristics of a smaller bead and more elongate abdomen, but in other respects has a close resemblance to the other sex; the node of the peduncle is incrassate, and elevated to the same height as the first segment, but is widest at its base; the tibiae and tarsi are pale rufo-testaceous as well as the mandibles and palpi.
Hab. Mexico.
