2 Orthonhapha Brachycera. 



horse-shoe-shaped, lying on the front side of the oral cone ; sometimes 

 it is not, or not distinctly, separated from the epistoma. The proboscis 

 may vary much in length, from very short to about as long as the 

 body; it is directed downwards or straightly or obliquely forwards, 

 sometimes it is curved somewhat inwards towards the sternum. 

 Labrum is about as long as the proboscis, it is strong, generally high 

 at the base, and semitubular, and it is three-pointed at the apex and 

 often curved downwards. In some genera (Clinocera, Dolichocephala) 

 it is very broad. Hypopharynx is likewise strong, canaliculated, more 

 or less lancet-like and pointed, and often curved downwards at the 

 apex; it may be incised near the apex in different ways, and some- 

 times it is very broad at the base and divided into two short lateral 

 lobes and a longer, pointed median process (Clinocera, Dolichocephala), 

 Maxillæ are present or absent; when present they are generally some- 

 what delicate, shorter or longer chitinous blades. Maxillary palpi are 

 al ways present, they are one- or indistinctly two-jointed. Labium al- 

 most of the same length as labrum ; the labella are shorter or longer, well 

 developed and generally cleft to their base. The connecting membrane 

 at the base of labium is sometimes very long; in rest it is infolded 

 but it is able to be drawn out often to an extent longer than labium 

 itself. Thorax is generally rectangular, sometimes nearly square; it 

 is sometimes very high and much arched above. Prothorax is gener- 

 ally small; sometimes it is more developed and neck-shaped. Meta- 

 thorax is likewise small, and there seems, at all events generally, to 

 be no chitinised metasternum. The thoracic disc has generally dorso- 

 central and acrostichal bristles or hairs in one or several rows; some- 

 times the disc is uniformly haired. Humeral, posthumeral, notopleural, 

 supraalar and postalar bristles are generally present, either all or some 

 of them ; rarely they are totally absent \ Scutellum has two or more 



I may give here some explanation. The præsutural depression is in the Empids 

 generally large and slightly impressed and often somewhat indistinctly hordered ; 

 it is however as a rule not difficult to make it out, at all events by comparison. 

 The bristles placed here I term, in accordance with Girschner, notopleural 

 bristles; (Osten Sacken termed these bristles posthumeral); somewhat behind 

 the humeri there is generally a bristle, my posthumeral bristle; but not rarely 

 there is a bristle more forwards and inwards; it is perhaps more correct to 

 term this the posthumeral and the other the præsutural. The supraalar and 

 postalar bristles need no explanation. 1 give the explanation because Bezzi 

 (Deutsch. Ent. Zeitschr. 1909. Beiheft, 86) uses other terms. The notopleural 

 bristles he terms præsutural; his posthumeral bristle is, I think, the bristle 

 inwards to the humeri mentioned above (as he says about it: „Posthumeral- 

 borsten, oder basser (bei diesen Fliegen) Intrahumeralborsten"); his ,Notopleu- 

 ralborsten oder Posthumeralborsten" is then my posthumeral bristle; in his 



