In the confusion existing as to the meaning of the various Entedonine genera, I think it best to define the sense in which Pleurotropis is employed in the following pages. The essential character of the genus is, I take it, the presence on the smooth propodaeum of two central keels, which diverge apically to meet the raised posterior edge of the segment. There are also present two lateral keels, as a rule strongly developed, running (inside the oval raised spiracle) along the edge from which the descent to the pleura begins. The lateral keels join the posterior edge above a generally slightly protruding angle inside the insertion of the metacoxae. The general shape of the propodaeum is transversely quadrate, not truncately triangular as in Entedon. The petiole, which joins the propodaeum by a distinct, though often very short, process, is pitted, quadrate or even sub-pentagonal in section. The proportion of the first abdominal tergal surface to the whole visible surface varies sexually and specifically from less than one-third to three-quarters.