ZooL— Vol. II.] WHEELER— DOLICHOPODID^. 7 



somewhat concave above the transverse suture, extends nearly one-fourth its 

 entire length below the lower corners of the eyes, and terminates in a 

 broad, rounded point. Antennae rather small; first and second joints yellow, 

 blackened along their dorsal surfaces; third joint wholly black, scarcely 

 longer than the first and bearing a slender, naked, subapical arista. Front 

 concave, metallic green, overlaid with white dust. Postocular cilia black 

 above, below rather long and stiff, yellowish white. Thorax metallic 

 green, more golden on the disc, covered with white dust, which forms three 

 large and conspicuous accumulations on either side, one on the humerus, one 

 in the posthumeral depression and another more elongate accumulation 

 above the insertion of the wing. Anterior fourth of thoracic dorsum covered 

 with very small, thick-set bristles. Acrostichal bristles distinct, in two rows, 

 each of which is bordered by a narrow brown vitta on its outer side as far as 

 the middle of the thorax. Dorsal bristles prominent; six in either inner row. 

 Scutellum metallic green, covered with white dust and bearing two stout 

 mesial and two weak lateral bristles. Abdomen not longer than the thorax, 

 metallic green, overlaid with white dust, which is very thin on the dorsal and 

 very thick on the lateral and ventral portions of the segments. Venter yel- 

 lowish. Hairs on the abdominal segments short, black. Pleurae deep, cov- 

 ered with a very thick layer of silvery white dust, so that the ground-color is 

 entirely concealed. Coxae yellow, middle and hind pairs darker towards the 

 base on their outer sides. All the coxse are covered with silvery white dust 

 like that on the pleurae. Fore coxae with a few black bristles near their bases 

 on their anterior inner surfaces and several larger ones near their tips. Legs 

 yellow, tarsi of fore and middle pairs from the tip of the first joint, hind tarsi 

 entirely and tips of hind tibiae, black. The separate tarsal joints on all the 

 feet bear one or two strong bristles at the tip on the plantar surface. Wings 

 long and narrow, somewhat pointed, grayish hyaline with yellow veins. The 

 costa is not thickened. Third vein bending down gently at its tip; distal 

 segment of fourth vein turning up from a distinct rounded angle about a 

 third its length from the cross-vein, then describing a slight curve and 

 descending somewhat to terminate a very short distance before the tip of the 

 wing. Attenuated tips of the fifth and sixth veins not reaching the posterior 

 margin. Posterior cross-vein somewhat nearer the apex than the base of the 

 wing and about its own length distant from the posterior margin measured 

 along the distal segment of the fifth vein. Halteres and tegulae yellow, the 

 latter with long black cilia. 



One specimen labelled " Grand Canon, Arizona," from 

 the collections of the University of Kansas. 



The female above described differs from the females of 

 P . jiabellifer O. S. and P. suferhus Aid., in having a much 

 longer face. In P. castus the face extends below the 

 lower corners of the eyes nearly as far as that of the male 

 P. superbus. Aldrich describes the female of his species 

 as having a face " ending in a point below, which reaches 

 fully to the lower edges of the eyes." In P. Jiabellifer, 



