34 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Skr. 



5. Antennal arista with a terminal lamel in the male, .signifer O. S. 

 Arista without a terminal lamel 6 



6. Third antennal joint of male as long as the thorax. 



xipheres, sp. nov. 

 Third antennal joint of male not as long as the thorax 7 



7. Hypopygial lamellae furcate rotundiceps Loew. 



Hypopygial lamellae simple, long and pointed, .effilatus, sp nov. 



36. Porphyrops xipheres, sp. nov. 



Plate II, Fig. 53. 



Male. Length 3.5 mm. ; length of wing 3 mm. Palpi small, dusted with 

 white. Face broad for a male, covered with silvery white dust. Antennae 

 black; first and second joints short, third joint flattened, as long as the 

 thorax, slowly tapering to the tip and covered with short and almost imper- 

 ceptible pile; arista terminal, very short, with short pubescence, its basal 

 segment somewhat thickened. Front black, rather opaque. Postocular 

 cilia abundant, snowy white. Thorax and scutellum blackish metallic green, 

 the latter with bluish reflections. Abdomen dark metallic cupreous green; 

 edges of the segments black; basal segments bearing long pale hairs on their 

 sides. Hypopygium shining black, with protruding appendages; lamellae 

 triangular, tapering, covered with erect hairs, black, each with a small white 

 spot near its base; internal appendages club-shaped. Pleurae thickly covered 

 with gray dust, except above the base of the middle coxae where the metallic 

 green ground-color is exposed. Coxae concolorous with the pleurae, only 

 their extreme tips yellow; anterior surfaces of fore coxae clothed with con- 

 spicuous silvery white hairs. Middle coxae each with a tuft of similar hairs 

 and a couple of stout, curved black bristles. Legs plain, yellow, anterior 

 tarsi from the tip of the first joint, the hind tibiae, which are somewhat incras- 

 sated, hind tarsi and hind femora on their upper surface near the tip, black. 

 Wings grayish hyaline, not narrowed toward the base; veins brown; third 

 and fourth veins nearly parallel. Halteres and tegulas yellow, the latter with 

 long white cilia. 



One specimen from Delaware County, Pa., June 8, 1892, 

 received from Mr. C. W. Johnson. 



This species may be readily distinguished from the other 

 described North American forms by the peculiar elonga- 

 tion of the third antennal joint. 



37. Porphyrops effilatus, sp. nov. 



Plate II, Figs. 54 and 55. 



Male. Length 3.5 mm.; length of wing 3 mm. Palpi and face covered 

 with silvery white dust; the latter very narrow. Antennae black, third joint 

 lanceolate, twice as long as broad at the base, clothed with very short pile; 

 arista apical, very little longer than the antennae, with scarcely perceptible 



