﻿92 uinnals of the South African Museum. 



small cheeks, which are clothed by dense hairs, dai'k yellowish above 

 and white below, the latter being the more developed ; beard white. 

 Proboscis entirelj^ black, thin, with small terminal labella, 3-4'5 mm. 

 long ; palpi black, long, tlie apical joint with short white hairs. Eyes 

 intimately connected. Thorax, scutelluni and abdomen deep black, 

 the last a little sliining, chiefly at the base of the segments ; they are 

 entirely clothed Avith dense, soft, equal, rather long white hairs which 

 from a front view have a silky sheen, without any dai'k bristles, even 

 on the al>domen ; the hairs of the end of the abdomen are narrowly 

 yellowish at the base ; venter Avith long hairs, but it is concealed under 

 the long hairs of the sides of the tergites. Genitalia black. Squamae 

 Avliite, Avith yelloAv Ijorder and long white fi-inge ; pleurae densely 

 clothed Avitli grey-dust. The black band of the knob of the haltères 

 is limited to the upper side. Legs entirely black, white-scaled, with 

 the femora white-haired and black-spinose ; middle femora with 2, 

 hind femora with 4-6 spines ; claws black, with a reddish base ; 

 pul villi dirty yellow. Wings hyaline, iridescent, a little Avhitish on 

 the basal half and along the fore border, with yellow veins ; base of 

 the costa Avith a short tuft of silvery hairs; upper branch of the 

 cubital fork a little retreating at base. 



GONARTHRUS CYLINDRICUS, Bezzi (1906). 



Easily distinguished from chioneus, Bezzi, on accovmt of the black 

 abdominal bristles and of the Avhite knol) of the haltères. 



Of this widely spread species there is a female specimen from South 

 Rhodesia, Gwelo, April, 1917 (Miss Skaife). 



CROCIDIUM, Loew (1860). 



This genus is not represented in the collection, but I have received 

 a specimen of the typical species from WilloAvmore (Cape), and haA'e 

 seen a new species with unspotted Avings from the same locality. Its 

 nearest ally is Gonarthrus, which, hoAvever, differs in the venation 

 being that of a Dischistus with a broad cubital fork and an open anal 

 cell. 



To Loew's description of the genus may be added : Occiput flat, not 

 inflated, briefly haired along the border. Ocelli disposed in an equi- 

 lateral triangle. Eyes of the male united for a long distance, with the 

 upper areolets enlarged and sharply separated from the smaller ones. 

 Antennae inserte«l at the centre betAveeu the eyes, approximate at the 

 base, Avith the third joint twice as long as the first. Face of the male 

 with long moustache. Thorax, scutellum and abdomen Avithout distinct 



