Empididae. 275 



difficult to see withoiit the microscope; their hind margin is slightly 

 incurved, and the Iower posterior corner is pointed. The incision in 

 the inner eye-niargin is distinct and not small. The vertex has three 

 ocelli, and some (four) bristles, or these latter are wanting. The 

 antennæ are inserted near to each other, about in the middle ; they 



Fig. 155. Antenna of Ch. hirta. X 90. 



are short, five-jointed ; the first joint is short, the second a little 

 longer and with bristles, which are longest below; the third joint is 

 ovate, dilated dovvnwards and compressed, it bears at the apex a 

 longer or shorter, two-jointed arista, the basal joint of which is very 

 short; the arista is directed somewhat downAvards. Epistoma is some- 

 what broad and broadened downwards, its Iower part is a little 

 arched; it is confluent with the jowls, which descend more or less 

 below the eyes. Glypeus is a small, nearly quadratic piece, excised 

 in the Iower margin ; it is not quite separated from the epistoma. 

 Proboscis is about half as long as the head is high, it is strong and 

 well chitinised, curved a little downwards and directed backwards, 

 towards the sternum. Labrum is as long as labium, strongly chitinised, 

 very high at the base and curved downwards towards the apex, it is here 

 divided into three long, claw-like points, the lateral are strong and have 

 a spine below in the middle, the median is less chitinized and beset 

 with bristles on the Iower side; hypopharynx is as long as labrum, 

 very strongly chitinised, black, and curved downwards with the pointed 

 apex; there are no maxillæ but one-jointed, ovate and compressed 

 maxillary palpi with long bristles. Labium has the basal part and 

 the labella of about equal length, the latter are cleft about to their 

 base, and they bear strong bristles; there is a somewhat large median 

 lobe between the labella. Thorax is slightly elongated, almost qua- 

 dratic, a little arched above. Pro- and metathorax small. Short bi- 

 serial acrostichal bristles are present, and generally longer uniserial 

 dorsocentral bristles, but these latter are fused with short hairs, 

 clothing the sides of the disc, and the dorsocentral bristles are some- 

 times not longer than the lateral hairs, and in this case they are not 

 distinct. A humeral bristle, a posthumeral, some notopleural, a supraalar 

 and a postalar bristle are present; sometimes the posthumeral bristle 

 is absent, and in one case (incana) there is only a notopleural bristle 



18* 



