﻿(Jih the Biii)ihi//ti(l Fiuiiiii of Soiilli Africii ( Dlpfera). 117 



PTERAULAX, geu. iiov. 



The present new genus is very near Cononedi/s and Aphoehantnsi ; 

 with them it forms a small group distinct in having no prominent face, 

 separated antennae, united eyes of male, a folded wing membrane, 

 short praefurca, and the second vein originating at an acute angle. 

 In general shape, however, this group agrees perfectly with that of 

 Plesiocera-Stouiyloniijia and with that of Petrorossla-Chionamuebd ; and 

 therefore I place all these 3 small groups of Becker with Lomatia in a 

 single group of Lomatiinae. 



The structural features of the new genus are as follows : Head 

 nearly spherical, broader than the thorax. Occiput conve.x and 

 prominent, with a very deep post- vertical furrow, bilobate above ; it 

 is excavated in the middle and destitute of fringe at the border. Eyes 

 bai'e, of great size, with a very developed indentation in the middle of 

 the hind border and with a well-developed Insection line ; in the male 

 ttiey have the upper inner areolets much broader and are united for 

 a rather long line ; in the female they are Ijroadly separated and have 

 equally small areolets. Ocellar tubercle prominent but small, ovate, 

 with three equidistant ocelli. Face broad, long, not prominent, pilose ; 

 genae very narrow ; chin broad and flat, destitute of long beard. 

 Antennae short, inserted a little above the middle of the eyes ; they 

 are Ijroadly separated at the base, but the first joint shows a pro- 

 tuberance on the inner side by means of which the antennae are 

 approximate ; the hairs of the under side are not tuft-shaped as in 

 Lomatia. The second joint is short and globose ; the third joint is as 

 long as the 2 first joints together, broadened and rounded at base, and 

 narrowed to form a point half as long as the first, which bears at the 

 end a well- developed, bi-articulate style. Mouth-opening of small 

 size, oval ; proboscis very short, shorter than the head, thick, with 

 bi'oad terminal labella ; palpi short and strong, less pilose, bi-articulate, 

 the apical joint ovate, about half as long as the first. Thorax convex, 

 with strong and long praesutural and supraalar bi'istles, and also 

 with 2 pairs of bristles in front of the scutellum ; metapleurae Ijare ; 

 squamae rather developed, with short fringe; scutellum developed, 

 with some bristles at hind border. Abdomen of conical shape, in the 

 male very narrow and obtuse, in the female more depressed, Ijrt^ader 

 and acute at end. Male genitalia of great size, rounded, closed ; 

 female genitalia with dense tuft of hairs. Hind border of the 

 abdondnal segments with more or less developed rows of bristles, more 

 developed in the female. Legs strong ; hind femora much spinose 

 beneath ; spicules of tibiae long and thin ; many long spurs at the 



