]2 Oithorrhapha brachycera. 



is lying ; I think this may be the remainder of the convex vein V, for 

 the rest obliterated by the coalescing of the concave veins IV and 

 VI to the discai vein. In Sciapus the convexity seems to lie on the 

 base of the upper branch of the fork. In some species of Hygroce- 

 leuthus and DoUchopus the discai vein is rectangularly broken, and 

 wlien the lower angle has a httle veinlet, we have here in reality the 

 beginning of a fork; also here the convexity is found on the vertical 

 part. When the vein is quite straight, the convexity is generally still 

 present, but in some genera with a quite straight discai vein {Achal- 

 cus, Thrijpticus, Medeierus, Acropsilus) it has disappeared, and thus 

 no remainder of the fifth vein is left. The vein I have termed the 

 anal vein, and which is usually termed so, is, I think, in reality the 

 axillary vein, since it seems to be distinctly convex; Redtenbacher 

 and Brauer figure it also as convex, Adolph on the contrary as 

 concave. 



The developmental stages of the Dolichopodidae are not well 

 known, and only of a few genera have either larvæ and pupæ 

 or only pupæ been observed {Sciapus, Neurigona, DoUchopus, 

 Tachytrechus, Hercostomus, Leiicostola, Porphyrops, Machaerium, Sy- 

 stenus, Thrypticus and Medeterus); of Hygroceleidhus, Tachytrechus 

 and Hercostomus they are for the first time described here, but only 

 the pupæ. The known larvæ are cylindrical; the body consists of 

 twelve segments; the head is small and retractile. The mouth parts 

 consist (Brauer) of mandibles and maxillæ with small paipi; also 

 small antennæ are present. No eyes. The abdominal segments or 

 most of them have on the ventral side a transverse swelling, acting 

 as prolegs. The last segment is generally a little swollen, with some 

 longitudinal furrows; it is more or less obliquely cut at the end, and 

 has here four triangular warts, squarely placed, the two lower are 

 generally the largest; sometimes there is a small, fifth w^art between 

 the two upper. The larvæ are amphipneustic with small prothoracic 

 spiracles, and likewise rather small posterior spiracles, lying at the 

 base of the upper warts. The larvæ thus in general bear resemblance 

 to the Leptid larvæ, but they may as a rule be known by the unequal 

 sized posterior warts, of which the two lower are the longest, or there 

 is a small wart between the two upper. According to Beling the 

 larva of Neurigona has no warts on the last segment. — The pupa 

 is free; it has the antennal sheaths lying at the front of the head 

 directed downwards, but generally slightly marked; they are provided 

 with some transversely compressed teeth. The head and the dorsal 

 side of thorax have some short, stiff hairs. At the front margin of 

 the thorax there are two long or very long, thin, cylindrical spiracular 



