Tachinidae. 47 



only present at base or stretching quite to the hind margin, and some- 

 times unequal in the two sexes. Abdomen has, except in few cases, 

 bristles in smaller or greater number; they may be both discai and 

 marginal or only marginal, and be present along the whole margin 

 or only on the middle, generally in the middle on the anterior seg- 

 ments, along the whole margin on the posterior; especially on the 

 fifth segment they may cover the whole dorsum or only be present 

 on the hind part or at margin. The number of the bristles and their 

 presence or absence on the various segments is of very great syste- 

 matic importance, but it must be born in mind that the bristles, 

 also on thorax, are rather liable to varying by being abortive or on 

 the contrary by presence of supernumerary bristles. When we speak 

 of the bristles on abdomen it is always those on dorsum; also along 

 the sides bristles are present, but they are of less or no importance 

 and generally not mentioned. — The legs are of common shape, 

 shorter or longer to rather long, and slender or more robust. Not 

 rarely the front tarsi in the female are broad and flat. The claws 

 and pulvilli are smaller or larger and often they are specially elong- 

 ated in the male, sometimes strongly. The empodium is small and 

 bristle-shaped. The legs have in most cases more or less strong bristles, 

 especially present on middle and hind femora in various ways and 

 on posterior tibiæ. On middle tibiæ there is as a rule a single ventral 

 bristle about the middle, this latter may sometimes be wanting, 

 very rarely in both sexes (f. inst. species of Carcelia), more often 

 only in the male. Also the hind coxæ show sometimes a character of 

 systematic importance as they are as a rule bare on posterior side, 

 but sometimes here finely hairy or with a couple of bristles. — The 

 wings show a venation of the common Muscid type; costa reaches 

 to the apex of the discai vein when this vein ends in the margin 

 (in Gastrophilus only to the cubital vein); the mediastinal vein ends 

 in costa; the cubital vein is unbranched, thus only one cubital cell; 

 the discai vein is bent upwards in the apical part, forming the apical 

 cross-vein; this latter either ends in costa behind the end of the 

 oubital vein or it unites with the cubital vein at the margin or more 

 er less before, the first posterior cell is accordingly open, closed or 

 petiolate with a shorter or longer peduncle. The cell may end at the 

 apex of the wing, or more or less to rather far before the apex. 

 The angle formed by the bending up of the apical cross-vein may 

 be rectangular or more or less obtuse or rounded; in rare cases it is 

 very rounded and the apical part bending slightly up, so that none or 



