94 PROF. M. BEZZI. 



the end ; the bristles are all black ; three pairs of frontals, the basal one directed 

 backwards, the two others forwards. Thorax black, punctate, with the following 

 ivory- coloured markings : — The complete humeral callus ; two narrow arcuate stripes, 

 one on each side of the dorsum, running from the suture to mid- way between the suture 

 and scutellum ; a rather broad mesopleural band ; and a single rounded hypopleural 

 spot (fig. 7). The thoracic bristles are black and there are four strong scapulars ; 

 the anterior supra-alar is as strong as the others. Scutellum entirely ivory-coloured, 

 only the extreme base black, with two long and strong black bristles. Halteres Avhite. 

 Abdomen black and punctate like the thorax ; hind border of the second segment 



Fig. 8. Dacus eburneus, Bezzi, sp. n. 



with a transverse entire yellow band, sometimes less distinct ; hind border of the third 

 segment ciliated ; posterior middle part of fifth segment yellow. Venter dark brown. 

 Legs yellow, the four anterior femora with a dark apical band ; front and hind tibiae 

 black, the middle ones yellow, with dark base ; base of all the tarsi whitish. Wings 

 with the fore band very dark and broad, extending without interruption to the fourth 

 vein, but leaving clear the inferior angle of the first posterior cell ; terminal portion 

 of fourth vein straight ; hind cross- vein short and straight ; anal band broad. 



Type cJ and an additional specimen from Uganda, Entebbe, 9.viii.l912 (C. C 

 Gowdey). 



7. Tridacus xanthopterus, sp. nov. (fig. 9). 



A strikingly distinct species, which seems to have some affinities with the 

 description of scaber, Loew, which, however, shows no anal brown stripe, but has 

 an infuscated small cross- vein. The more striking peculiarities of the present species 

 are the colour of the thorax, which is almost destitute of any yellow marking, except 

 a very narrow mesopleural line, even the scutellum being of a brown colour, and the 

 colour of the wings, which are suffused with a yellowish tinge on the disk. There is 

 some affinity with the species of the first group (lounsburyi, etc.), as is shown also by 

 the thin scapular bristles. 



$. Length of body, 9 mm. ; length of wing, 8-5 mm. ; breadth of wing, 3 mm. 



Body of a uniform dark reddish brown colour, densely punctulate, and clothed 

 on the disk of the abdomen and thorax with short yellowish pubescence. Face and 

 frons of a more yellowish colour, occiput reddish, with a narrow yellowish border ; 

 frons with three pairs of small black dots on the sides, a blackish central spot and 

 a black ocellar transverse stripe ; lunula brown ; face unspotted, v/ith only a narrow 

 blackish line on the inner border. of the antennal grooves ; peristomial black spot well 



