CERATOMYIELLA AND PAEADIDYMA EEINHARD 13 



the main row ; vibrissae situated on oral margin ; antennae as long as 

 face, basal segments yellow, third brownish, thickly covered with 

 dense pale pubescence and about seven times longer than second 

 segment; arista about as long as third antennal segment, thickened 

 on proximal third, reddish, basal segments darker, short but dis- 

 tinct; eyes bare; cheek in profile about one-fifth the eye height; 

 proboscis short ; palpi slender, pale yellow ; back of head subshining 

 above, gray pollinose and pale haired below. 



Thorax and scutellum black, dusted with gray pollen ; mesonotum 

 marked with two heavy black stripes, which extend from the anterior 

 margin to base of scutellum without interruption at suture ; chaeto- 

 taxy as in C. conica; postscutellum thinly gray pollinose; no infra- 

 squamal hairs ; calypters transparent, faintly tawny. 



Abdomen rather slender, shining black; intermediate segments 

 with bluish-white pollen bands on basal fourth above, becoming 

 wider on the sides and venter ; fourth segment pruinose on proximal 

 third; two basal segments each with a pair of median marginal 

 bristles; third and fourth with a marginal row; no discals; genital 

 segments black, small, and retracted. 



Legs rather long and slender, blackish; front claws and pulvilli 

 short but distinct. 



Wings tinged with brown on anterior margin, grayish hyaline 

 behind ; veins bare except third, which is haired to small cross vein ; 

 hind cross vein perpendicular to fourth, joining it midway between 

 bend and small cross vein ; apical cell closed, the petiole nearly one- 

 third the length of the broadly concave apical cross vein, reaching 

 costa shortly before tip of wing; costal spine small. 



Length. — i mm. 



Reviarks. — Redescribed from two males in my collection from the 

 West Indies, donated by D. G. Hall ; labeled " Mustique Island, 

 May." 



The species varies considerably in the degree of infuscation of the 

 wings. Four specimens in the United States National Museum, ac- 

 cording to Dr. J. M. Aldrich, all have the wings more distinctly 

 infuscated than described above, agreeing better in this respect with 

 Williston's description. The species is closely related to conica^ 

 from which it is readily distinguished by the black legs, longer 

 petiole of apical cell, and other characters. 



I have not seen any specimens of the female. The type locality 

 is St. Vincent, British West Indies. 



(3) CERATOMYIELLA BICINCTA, new species 



Male. — Front at vertex 0.297 of the head width (one specimen), 

 not prominent at antennae; parafrontals gray pollinose to vertex, 



