﻿I'O Annals of the South African Mnseiim. 



A male specimen from Kimberley (Cape) Marcli 14th, 1912 (J. H. 

 Power), and a female from Potcliefstroom (Transvaal) (T. Ayres). 



Length of body 7-8 mm. ; of wing 6-7 mm. Occipital border with 

 very long yellow hairs which form a complete crown ; ocellar tuft 

 yellow in both sexes, but in the male a little dai-ker. Face very short, 

 with entirely yellow hairs, continued over the very narrow cheeks ; 

 beard short, yellow ; eyes of male intimately connected ; f rons of the 

 female less broad than the eye, clothed with dense golden yellow 

 tomentum and with erect yellow hairs ; the hairs of the cheeks in the 

 female ai-e white. Antennae entirely black, the first joint with yellow 

 hairs, those of the upper side very short, those of the under side very 

 long; third joint longer than the first two joints taken together, 

 linear, obtuse at end, not narrower than the second at base, with a 

 very minute style. Proboscis black, 2 mm. long ; palpi black, pale- 

 liaired. Thorax and scutelluni wholly deep black, clothed with equal, 

 dense and rather long yellow hairs, those on the back being pale 

 shining if viewed from the front ; the hairs on the pleurae are less 

 pale ; metapleura bare, but concealed below the mesopleural and 

 squamal tufts; there are no distinct bristles. Squamae dirty-whitish, 

 Avitli long yellow fringe ; haltères yellow, with a white knob. Abdomen 

 of conical shape, entirely black, clothed with hairs like those of the 

 thorax, which on the venter are shorter and rarer ; male without, 

 female Avith distinct and long, black, bristly hairs at the hind borders 

 of the segments ; male genitalia black, yellow-haired ; female genitalia 

 with broad black lamellae, the upper one rather shining and golden- 

 fringed at apex. Legs black, with yellowish scales, whitish hairs and 

 black spines on femora; middle femora with 1, hind femora with 2-3 

 spines on the apical half. Wings entirely hyaline, narrowly yellowish 

 near the base ; veins yellow, darkened at end ; upper branch of the 

 thii'd vein a little retreating at base. 



GONARTHRUS CYCNUS, Bigot (1892). 



Allied to the preceding, but distinguished by the very long, white 

 pubescence of the entire body and by the black knob of the haltères 

 in the male sex. 



The present species Avas briefly, but reeognisably, described from 

 the Cape. There are in the Museum Collection numerous specimens of 

 both sexes from Stellenbosch (Cape) (L. Pcringuey), Potcliefstroom 

 (Transvaal) (T. Ayres), Namaqualand, O'Okiep (Cape), October, 

 1890 (K. M. Lightfoot). One of these examples Avas labelled by 

 Bigot as Boinhylius niveus, Macquart — an impossible thing, however, 



