278 J. M. ALDRICH. 



Abdomen ratlier coppery, with a uniform covering of thin grey dust, which in 

 side view seems more concentrated on the sides of the segments; it does not hide 

 the metallic color to any great extent. The abdomen is noticeably robust and 

 rather short. Hypopygium small, black, with small, black, rounded lamellae. 

 which, however, have a long black filamentous prolongation at the inner basal 

 angle, usually difficult to perceive. This has a backward direction, and can 

 usually be seen when the abdomen is viewed nearly from above. 



Legs yellow, the fore coxjb scarcely infuscated at base, middle and hind ones 

 almost wholly black; tarsi only a little infuscated. 



Wings greyish, venation of the typical form with considerable concavity back- 

 ward in the last section of the fourth vein. 



Length 2.9 mm. 



Female.^ln these there is a fairly distinct median line on the thorax, other- 

 wise no materia! differences. 



Six tuales, two females, New Bedford, Mass., collected by Dr. 

 Hough. 



The species is closely related to propinquus Wheeler from Florida, 

 but the latter has a distinct stripe on the thorax in both sexes, the 

 hind femora infuscated above for the entire length, etc. Profe.ssor 

 Wheeler's description of prophiqnus does not mention the thoracic 

 stripe, but it is very prominent in two males that Mrs. Slosson sent 

 me from Florida. 



Pelastoiieiirus proxiinus n. sp. 



]\fale. — Face moderately wide, with brown dust, which in some specimens is a 

 little paler close along the lower edge; antennae yellow, the third joint some- 

 what elongated, brown at the tip; arista moderately plumose. Front shining, 

 somewhat steel-blue on the sides. Cilia of the inferior orbit black. 



Thorax dark green, with the usual dark spot on the side, and white one in the 

 sutural groove; before the scutellum with a distinct violet tinge; pleurae black, 

 with grey dust; halteres and tegulae yellow, cilia of the latter black. 



Abdomen bronze-green, on the sides of the segments with patches of white 

 dust; hypopygium elongate, black, the lamellae entirely black, rather long, a 

 little pointed, with a thick row of slender, long blackish hairs on the edge. 

 Above the lamellae are two shorter filament-like organs (the " inner lamellae " of 

 Loew), dark brown in color, which have some .slender brown hairs in one or two 

 tufts near the tip. 



Legs yellow, middle and hind coxae about half black, tarsi very slightly infus- 

 cated. 



Wings suhhyaline, fourth vein bent gradually about its middle, ending consid- 

 eralily before the tip. 



Length 2.9 mm. 



Female. — Face brown in the middle, whitish along the sides; otherwise not dif- 

 fering materially from the male. 



Five males, one female, Opelousas, La., from Dr. Hough. 

 Except for the lamellae being so very different, 1 should have 

 taken this for Pelastoneurus furcifer Lw. 



