Empididae. 3 



marginal bristles. Metapleura have bristles or short hairs, or they 

 are quite bare. Abdomen is generally more or less slender, sometimes 

 more robust; it consists of eight segments, sometimes the last or two 

 last are hidden. The first dorsal segment is as a rule shorter than 

 the second and sometimes broader. The male genitalia may be of 

 very various construction ; they seem always to originale from seg- 

 ments foUowing after the eighth, but they may sometimes influence 

 the shape of one or several of the anterior segments. Often they 

 consist of two pairs of more or less distinctly separated lamellæ form- 

 ing an upper and a lower forceps, and below there may be a ven- 

 tral lamella; penis is often more or less thread-like, curved upwards 

 and sinuous; but often the genitalia are differently eonstructed, so 

 that these parts cannot be discerned, and they may be more or less 

 unsymmetrical. In the female the abdomen is more or less pointed, 

 terminating with a smaller or larger ovipositor generally with two 

 styliform lamellæ at the end. The legs may be very variously deve- 

 loped; they are shorter or longer, often long and slender, especially 

 the hind pair. They show not rarely sexual dimorphism, thus they 

 may in many cases in the male show structural peeularities such as 

 thickened femora , tibiæ or metartarsi , or they may have spines or 

 tufts of hairs; in the females they may in the genera Enipis and 

 Rhamphomyia often be more or less pennate from scaly hairs. In 

 other cases the legs may show a special development in both sexes, the 

 front coxæ may be elongated, the front or the anterior femora thick- 

 ened and together with the tibiæ have a special armature making them 

 adapted to raptorial use. The legs are shorter or longer haired and 

 have often bristles to a varying degree. A])ical spurs on the tibiæ 

 may be present or absent, but when present they are not large. 

 There are two claws, two well developed pulvilli and a generally 

 small , lobe-, claw- or bristle-shaped empodium , generally bearing 

 bristles; in Clinocera the empodium is more or less pulvilliform. The 

 wings have the costa generally reaching only about to the apex, some- 

 times continuing more or less distinctly all round the margin. The 

 venation may vary greatly; the mediastinal vein reaches the margin or 

 is abbreviated; the subcostal vein is longer or shorter; the cubital 

 vein is either forked or unforked, sometimes the upper branch is 

 connected with the radial vein; there may thus be one to three cubital 

 cells. The discai vein is forked or unforked, and there are three or 



introductory remarks he teims it npl., but it seems to me to be the same bristle 

 which he terms ph under Xanthempis. If any bristle in the Empids should be 

 termed præsutural it can only be the one I term here the posthumeral bristle. 



1* 



