4 Orthonhapha brachycera. 



four posterior cells; discai cell present or absent; when present it is 

 always closed below by the iipper branch of the postical vein; it 

 sends two or three veins to the margin, the lowermost being the upper 

 branch of the postical vein ; when it sends two veins the upper is in 

 a few cases forked. The basal celis are shorter or longer; they may 

 be of equal length or sometimes the first or on the contrary the 

 second is the longest. The anal cell present or absent, but when 

 present always short, never reaching the margin; it may be shorter, 

 of equal length with, or longer than the second basal cell. Anal vein 

 reaching the margin or abbreviated or quite absent. The lower branch 

 of the postical vein either recurrent and more or less parallel with 

 the wing-margin , or meeting the anal vein at a right angle ; when 

 the anal cell is absent the lower postical branch may be present or 

 absent. Stigma present or absent. The axillary lobe large or smaller, 

 sometimes quite absent and the wing more or less cuneiform in shape. 

 Alula generally wanting, sometimes present but very small. — In 

 single cases the wings may be very broad and of curious shape, 

 generally only in the female, and sometimes the venation may be 

 different in the two sexes with regard to the size and shape of the 

 discai cell. In other rare cases the wings may be small, narrow and 

 a little abbreviated. — The alar squamulæ are small, fringed at the 

 margin, very rarely bare; the thoracic squamulæ not developed, but 

 the frenulum more or less distlnct, sometimes a little broadened 

 towards the angulus. The balteres not covered. In rest the wings 

 lie parallel over abdomen, one covering the other. 



The developmental stages of the Empididae are not well known, 

 and for most of the genera they remain still to be discovered. The 

 known larvæ are cylindrical, more or less spindle-shaped ; they con- 

 sist of twelve segments (Beling, Brauer). The head is small and 

 retractile; the mouth parts consist (Brauer) of mandibles and maxillæ 

 with small palpi; there are also small antennæ but no eyes. Most of 

 or all the abdominal segments have on the ventral side small trans- 

 verse swellings (Kriechschwielen). The last segment is more or less 

 rounded and has below on the hinder side a smaller or larger, gener- 

 ally triangular tooth or wart. The larvæ are amphipneustic with 

 small prothoracic and likewise rather small terminal spiracles on the 

 last segment above the tooth mentioned. The pupa is free; it has 

 the antennal sheaths lying below on the front side of the head and 

 directed to each side; above them there are some small tubercles, 

 each with a hair; thorax has generally some long bristles. The abdo- 

 minal segments have above girdles of small teeth and between them 



