OF WASHINGTON. 319 yellowish hairs and almost identical in form with those of y-inversus (Fig. 7, b, c}. Of this species I have seen but a single male, taken in 1884, by Mr. Morrison, in Colorado. In general appearance, as well as in the genital characters, it seems to be quite closely related to P. y-inversus. Prodoxus sordidus, n. sp. IMAGO. $. Expanse, 8-10 mm. ; Q, 11-13 mm. General color, creamy-yellow, the females showing the most white. A more or less distinct dusky or blackish posterior margin to the secondaries, the dark color broadening toward the apex. The undersur-faces have a tendency to metallic reflection and the darker color of the hind border of the secondaries is repeated. Abdomen grayish-brown dorsally, with iridescent reflection. Anal segment of 9 reddish-brown, obliquely truncate from above, the tip rounded. Ovipositor yellowish-brown, slender and finely denticulate along the upper edge. Male claspers similar in shape to those of decipiens but more slender, the base comparatively broader and the apex more abruptly rounded; the basal side piece nar rower and pointed at tip ; the posterior edge with from 3 to 5 small slender teeth. Described from 5 males and 5 females. I first found this species in the flowers of Yucca brevifolia on the same occasion of the discovery of Pronuba synthetica, while other specimens were subsequently obtained by Mr. Koebele. In general appearance the species seems nearest related to P. cinereus, being, how v^er, much paler, with the greater portion of the hind wings w lite. COLEOPTEROUS LARVAE WITH SO-CALLED DORSAL PRO-LEGS. BY C. V. RILEY. I have recently received from Mr. D. W. Coquillett, of Los Angeles, California, the larva of Mordellistena pustulata^ which he found in the dry stalks, apparently of the previous year's growth, of Xanthium strumarium, and as they exhibit a peculiarity, viz., the possession of dorsal fleshy processes having the appearance of prolegs which belongs generally to the larva? of this genus, I have thought it well to exhibit them to the Society, as also some other Iarva3 which possess similar characteristics. Many of the members will remember that at the 1890 (Indianapolis) meeting of the A. A. A. S., at which I was not present, Prof. H. Osborn read a note (published in the Canadian Entomologist, Vol. XXII, 1890, pp.