44 Tachinidae. 



phaga). The pleiira are more or less hairy, the propleiira below hiime- 

 ral calliis hairy in Calliphorinae (except in Pollenia and the foreign 

 group Rhynchocalliphorinae Vill.), bare in the other subfamilies 

 (except in species of Echinomyia and in Helicobosca); the postalar 

 dechvity i. e. the vertical space below the postalar cailus is hairy in 

 Calliphorinae and with more or fewer hairs in Sarcophaga and Blaeso- 

 xypha, otherwise bare, as far as I have seen. On the pleura there is 

 a vertical row of bristles just in front of the mesopleural suture. 

 Above on mesopleura, under the wing-root (pteropleura), there is 

 generally a tuft of hairs or smaller or larger bristles, sometimes a 

 single long bristle. On sternopleura there are most often three sterno- 

 pleural bristles placed as 2 — 1, but sometimes there are four; in 

 some cases there are only two sternopleurals or even one but only 

 exceptionally none at all; when three they are sometimes placed as 

 1 — 1 — 1 {Sarcophaga). On propleura there is one or more prothoracal 

 bristles above front coxæ, and at the lower anterior corner of meso- 

 pleura a stigmatical bristle or a couple. Hypopleura have a vertical 

 row of more or less numerous hypopleural bristles, and this is a very 

 important character (first detected by Osten Sacken), dividing the 

 Tachinids from all other Muscids; only in the Oestrid subfamilies 

 they are replaced by hairs and in Gastrophilus wanting. Hypopleural 

 bristles are otherwise only found in Eginia and in a reduced form 

 in Orygma luctuosa, both for other reasons not belonging here. (In 

 some foreign forms of Antkomyidae there may be a spot of hypo- 

 pleural hairs like those found in some likewise foreign Tachinidae). 

 Scutellum has a number of marginal bristles of very various develop- 

 ment as to size and number; very often the number is four on each 

 side (termed after Girschner: Wien. Ent. Zeitg. XX, 1901, 71 the 

 basal, the lateral, the subapical and the apical), but the number 

 may be larger, and it may be strongly reduced; the apical are often 

 Crossing, but may also be parallel or diverging. On the disc there 

 are sometimes a pair of discai and of preapical bristles. (When the 

 number of the marginal bristles is less than four it is sometimes 

 difficult or impossible to decide which are the wanting bristles, but 

 the lateral bristle is the last appearing). — Abdomen is of very various 

 shape, from almost globular to long and elongated cylindrical, and 

 it may sometimes be more or less flattened. The tergites are always 

 most developed and bend down on the ventral side, the sternites 

 being small (broader in Cynomyia and in Gastrophilus). Otherwise 

 the facts are here different; in some groups the sternites lie imbedded 



