594 Professor Williston on the 



the second joint stout ; third joint oblong ; ai-ista with seven or 

 eight rays. Face convex above, gently convex from very near the 

 margin of the eye, the orbital margin being exceedingly narrow ; 

 on the lower part the face has very fine grooves. Mesonotum and 

 scutellum thinly yellowish-dusted in an oblique light. Abdomen 

 deep shining metallic-green ; fourth segment longer than the third, 

 the fifth about half the length of the third. Legs black ; the front 

 cox£e, the base of the front femora, the tip of the four posterior 

 femora, the four posterior tibire wholly, and the four posterior 

 tarsi, except the distal joint, yellow ; front tarsi stout and deep 

 black, like their tibiae. Wings greyish hyaline ; third section of 

 the costa as long as the second. Length 2 mm. 



One specimen. St. Vincent. 



4. Psilopa aciciilata. 



Psilopa aciculata, Loew, Monogr., i., 142. — Cuba. 

 (PI. XIII., fig. 140, wing.) 



^ , $ . Head shining metallic-green. Vertical border very 

 sharp. The bristles of the front are confined to the vertex, two 

 on the ocellar tubercle and two on each side. The vertical triangle 

 is bounded by a well-marked groove, its anterior angle truncated 

 below, just above the base of the antennae, and continuous to the 

 eyes on the side of the face below. The face is narrower than the 

 front, the eyes approaching each most at a little distance above 

 the oral margin ; the face is smooth, gently convex transversely, 

 and with parallel sides from the grooves, which are continuous 

 from the front; nearly opposite the narrowest portion there is a 

 single black bristle on each side. Antennae yellow ; the second 

 joint above and the third in front, reddish ; arista black, with 

 about six rays. Mesonotum and scutellum bronze-black, but little 

 shining, finely aciculate ; pleurae more shining green-black. Abdo- 

 men brilliant metallic-green, with coppery reflections ; first seg- 

 ment very short, the second, third, and fourth successivsly longer, 

 the fifth again short. Legs black, the knees, tip of tibite and all 

 the tarsi yellow. Wings with a distinct yellowish tinge, the basal 

 portion obliquely across to about the middle of the anal cell, 

 blackish ; second and third sections of the costal vein of nearly 

 equal length. Length 2 mm. 



Five specimens. St. Vincent. This species is rather 

 aberrant from other members of this srenus in its colour 

 and structure of the head. 



