219 



subcordate at base, very strongly depressed, the vibrissal plates situated 

 about half way between the middle and the base; ovipositor very short,, 

 not protruded, and enclosed by the fifth ventrite which reaches to the 

 apex but is not at all compressed. 



Legs of usual length and without special modifications ; the middle 

 tibiae moderately enlarged at apex, the spur as long as the first tarsal 

 joint; the middle tarsi thicker than the other tarsi. Wings with the cos- 

 tal cell wide ; the discal ciliation moderately dense, .sparser on the basal 

 part before the narrow speculum ; marginal fringe very short and thick ; 

 marginal vein nearly punctiform or slightly longer than thick; stigmal 

 moderately long or about equal to the marginal and postmarginal veins 

 combined, somewhat enlarged at apex with a spur on the upper side, 

 postmarginal about two-thirds as long as the stigmal ; hind wings with 

 the costal cell nearly absent. 



Head and thorax very finely reticulate, the abdomen slightly more 

 coarsely reticulate, all parts, especially head and notum, strongly shining; 

 frontovertex with a few scattered, minute and shallow pin-punctures, the 

 mesonotum with minute, seriated, setiferous punctures. Eyes with a fine, 

 rather thick pubescence ; rest of head with longer, moderately thick pu- 

 bescence; mesoscutum and scutellum with numerous seriated, bristle-like 

 hairs ; abdomen finely, sericeously pubescent especially on the sides and 

 apical margin ; the pubescence blackish throughout and not conspicuous. 

 Coloration metallic bluish and greenish black. 



Male : Similar to the female except in the very peculiar and highly 

 specialized head. This is a little longer than wide and subcircular in 

 frontal view, very thin towards the mouth fronto-occipitally and grad- 

 ually thickening above where it becomes about three times as thick as 

 at the oral margin, the dorsal surface very strongly convex ; fronto- 

 vertex nearly as wide as long, with the frons very prominent and pro- 

 tuberantly produced forward beyond the eyes ; the ocelli arranged in a 

 large, equilateral triangle, the anterior one on a line with the anterior 

 dorsal corners of the eyes, the posterior pair close to the eye-margins 

 and remote from the rounded occipital margin ; eyes subtriangular with 

 the posterior orbits rounded ; cheeks as long as the eyes ; face str'ongly 

 produced upward beyond the eyes and joining the frons in an acute 

 angle, strongly obliquely reflexed and concave from the frontal angle to 

 the antennal sockets as seen in side view, the upper part between and 

 beyond the eyes flat from side to side, the remaining part above the 

 antennae concave from side to side, the part below the antennae moder- 

 ately convex. 



Antennae inserted very far apart on the outer margins of the face 

 next to the cheeks, and half way between the base of the mandibles and 

 the eyes ; short and strongly clavate ; scape very short and incrassate, 

 but little longer than thick, reaching not more than one-third of the dis- 

 tance to upper margin of face, in cross-section subtriangular, the lower 

 side slightly hollowed to receive the pedicel, the other two sides convex, 

 the outer margin in outline straight, the inner margin forming an arc 



