Empididae. 201 



hairs. The antennæ are inserted near to each other in the middle; 

 they are three-jointed, the two basal joints are short, the first cyhndri- 

 cal, the second almost globular, the third joint is about as long as 



Fig. 81. Antenna of O.glahricula. x 80. 



the two basal together; it is ovate and bears above, somewhat behind 

 the apex, a long arista, which is, so far as I could detect, not articu- 

 lated to the joint. ^ Epistoma is high and very narrow; jowls are 

 not developed, the eyes going quite to the moiith aperture. The 

 proboscis is short, only just reaching out of the mouth aperture; 

 labrum is strong, semitubular, high at the base and with a three- 

 lobed apex; hypopharynx is of the same length, pointed to.wards the 

 apex. I could not detect the laciniæ of the maxillæ on the dried 

 material I had for examination; the maxillary palpi are one-jointed, 

 short; labium is about of the length of labrum, with small labella. 

 Thorax is rectangular, high and strongly arched above. There are 

 very thin and short uniserial dorsocentral and biserial acrostichal 

 hairs; there are aiso small and inconspicuous humeral, notopleural, 

 supraalar and postalar hairs. Scutellum has six marginal bristles. 

 Metapleura with short, fme hairs. Abdomen is in the male long and 

 slender, cylindrical and consisting of eight segments, the eighth is 

 small; the exterior genitalia are small, consisting of a pair of some- 

 what complicated lateral lamellæ, forming a kind of forceps. In the 

 female the abdomen is thicker, somewhat compressed, likewise con- 

 sisting of eight segments and terminating with two small and short 

 lamellæ. The legs are long and slender, the hind legs the longest. 

 They are densely haired, but there are no specialised apical spurs 

 on the tibiæ. There are two claws, two pulvilli, and a small, linear, 

 pointed empodium, bearing bristles below. The wings have the 

 mediastinal vein not reaching the margin; the cubital vein is unforked, 

 thus one cubital cell; the discai vein likewise unforked, so that there 

 are only three posterior cells; sometimes a little veinlet is present, 

 indicating a beginning of an upper branch of the discai vein. The 

 discai cell sends only two veins to the margin, the lower is the upper 

 branch of the postical vein, which closes the discai cell below, The 



^ I have examined antennæ treated with potash under a magnification of more 

 than 100, and I could detect no articulation ; in spite of this result I feel 

 not quite certain, and in the related Leptopeza the antennæ are five-jointed, 

 the arista being two-jointed and articulated to the third joint. 



