14 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



of each segment. Sixth segment wholly covered with white dust. Hypo- 

 pygium as thick and very nearly as long as the abdomen, black, dusted with 

 white. Lamellae subtriangular, black, with rather long yellow bases and 

 their edges ragged and fringed with long black hairs. Inner appendages 

 and the portion of the hypopygium from which they arise, mostly yellow. 

 Pleurae black, thickly covered with white dust. Coxae also covered with 

 white dust, the middle and hind pairs black with yellow tips, the fore pair 

 yellow except at the base on the outer side where they are slightly infuscated. 

 Legs plain, yellow; tarsi infuscated from the tip of the first joint. In some 

 specimens the tips of the hind femora are infuscated on the upper side. 

 Wings grayish hyaline with the usual Pelastoneuran venation. Halteres and 

 tegulae light yellow, the latter with prominent black cilia. 



Female. Length 3.5-3.75 mm.; length of wing 3.5-3.75 mm. Palpi larger, 

 face broader and more projecting than in the male; the former brown, cov- 

 ered with silvery white dust; the latter chocolate colored with a band of sil- 

 very white dust on either side along the orbit. Wings somewhat more 

 infuscated than those of the male. In other respects the coloration of the 

 two sexes is very similar. 



Seven males and ten females collected at St. Augustine, 

 Fla., and sent me by Mr. C. W. Johnson. The species 

 resembles P. argentiferus Aldrich, from St. Vincent. W. I. 

 Aldrich's species, however, has the hind tibise strongly 

 infuscated, the concave, upper portion of the face in the 

 male shining green, the black on the antennae more exten- 

 sive, and a pair of white spots just behind the roots of 

 the wings. The lamellae of the hypopygium, too, in P. 

 argentiferus have a very different structure, to judge from 

 Aldrich's descriptions. 



14. Pelastoneurus pictipennis, sp. nov. 



Plate I, Fig. 19; Plate II, Fig. 25. 



Male. Length 3 mm.; length of wing 2.5 mm. Proboscis rather small, 

 retracted, piceous. Palpi large, blackish, covered with gray dust. Face con- 

 cave above the suture, projecting somewhat below, black, covered with white 

 but not very brilliant dust. Antennae reddish, third joint blackened towards 

 the tip; arista densely plumose, tapering, not quite as long as the face. 

 Front opaque dark brown. Postocular cilia black, not very conspicuous. 

 Thorax shining black, violet posteriorly, on either side with a velvety black, 

 dumb-bell-shaped patch and a round silvery white spot in the posthumeral 

 depression. Scutellum shining steel blue with a median longitudinal velvety 

 black band. Abdomen rather short and thick, shining black with violaceous 

 reflections, each segment with a large patch of white dust on its side. 



