214 C R, Osten Sacken: Diptera 



in front, the face is a little narrower above than below, antennal 

 foveae deeply marked, descending down to the peristomium, divergent, 

 leaving but a narrow orbit between them and the eyes; the interval 

 between the foveae is smoothly convex; cheeks narrow. 



Oral opening large, nearly circular, clypeus generally with- 

 drawn; peristomium almost imperceptibly arched in front but not up- 

 turned; palpi elongated, narrow, flattened. 



Front broad, gradually narrowed towards the vertex, its sides 

 forming gentle curves (the boundary of the eyes, on both sides, forms 

 a figure not unlike a lyre, contracting upwards, and then expanding 

 again on the top of the vertex); lower portion of the front turgid; the 

 lunula occupies nearly one-third of the breadth between the eyes. 

 Ocelli not far from the edge of the vertex. 



Eyes glabrous, descending very low (hence the narrow cheeks); 

 in life, they are uniformly green, changing into purple. 



Antennae: scapus small, third joint very long and narrow, linear, 

 reaching beyond the peristomium ; arista about once and a half the 

 length of the third joint, finely and densely pubescent (white in both 

 species described below). 



Thorax about twice as long as it is broad; lateral transverse 

 suture rather deeply marked, connected by a transverse depression. 

 Scutellum a little broader than long. 



Chaetotaxy: Head, only two pairs of vertical bristles of mode- 

 rate strength; the rest wanting. Thorax: no humeral bristle; post- 

 humeral, two; supra-alar, three; antescutellar, two; mesopleural one. 

 Scutellum, six bristles. 



Abdomen elongated, slender, about as long as head and thorax 

 together; without any bristles; four segments, the first being the lon- 

 gest; the second of the same length as the third; the fourth a little 

 longer. The male hypopygium is almost withdrawn in the fourth seg- 

 ment. In the female, the abdomen is broader in the middle than at 

 the ends, the first segment of the ovipositor flattened, triangular; the 

 tip of the ovipositor is slightly enlarged and bears two pairs of micro- 

 scopic hairs. 



Legs, of moderate length and strength; the hind femora not in- 

 crassate; front coxae rather long, moveable, inserted very near the 

 neck. Tegulae represented by a narrow strip. Wings. Costa and 

 first vein beset with short hairs; third vein with a series of minute 

 bristles on its proximal half; auxiliary vein closely approximate to the 

 first, ending in the costa a little before the middle of the wing; 

 beyond this spot, the first vein converges very gradually towards the 

 costa, forming a long and exceedingly narrow stigmatic costal cell, 



