114 H. C. EFFLATOUN. 



hairs ; the pubescence on their dorsal surface is mainly blackish, 

 much longer, and the characteristic metatarsus bears on its sharp 

 ridge a remarkable fringe of long, black, erect and tufted hairs. 



Wings pellucid, rather greyish, with the base of the veins 

 light brown and the subcosta and stigma brownish ; Radius 4 + 5, 

 slightly dipped. Squamulas and their fringes white, and their 

 margins yellow. Halteres yellowish-white. 



Female: Very similar to the male but the dust and pubescence 

 on t lie frons and vertex is usually yellowish or even tawny -yellow. 

 The hind metatarsi, although nearly as swollen as in the male, are 

 more rounded and do not possess that remarkable sharp dorsal 

 ridge with its characteristic black fringe. 



Lengl li from 8 to 9,\ mm. 



/•;. vestitus was originally described from West Africa (Rio 

 Cassine Portugese Guinea), where it lives together with a closely 

 allied species: E. obliquus. Hezzi (1912)* states that he had received 

 from Becker specimens from Egypt of the species described above 

 (vestitus) which were erroneously classified as obliquus. Moreover 

 Becker (1902;' ' describes the female of E. vestitus under the name 

 of obliquui and this description corresponds entirely with that 

 of vestitus 



E. vestitus is not a common species in Egypt and is rather 

 local. It is a very interesting fly owing to the fact that it closely 

 mimics the flight of Hymenoptera, and even to a practised eye it 

 is a very difficult matter to distinguish them. I have watched it 

 at Marg flying above Polygonum equiseti folium; it does not remain 

 motionless for a second, but continuously moves and vibrates its 

 wings ; it rests on the flowers for a short time and suddenly darts 

 away and sits on the sand and then back again on the flowers, 

 repeating this performance over and over again. 



There is no doubt that the larva feeds on decaying vegetable 

 matter.*** 



I have captured the adult at Shoubra, Marg, Kerdace, 

 Wadi Hoff, Mariout, Fayoum and I believe it to be more widely 

 distributed. My dates extend from April to October. 



It is known to occur in Syria, Greece, West Africa and no 

 doubt it occurs in many other localities, but, owing to its close 

 resemblance to E. obliquus, probably it occasionally has been 

 confused with the latter. 



*M. Bkzzi: Ditt. raccolti d. Leo. Fea, 4?. 44. ,442). (443). 37. (1912). 

 **Th. BECKER: Mitteil. Zoo], Mus. BerL, II. 87. 123. "(1902). 

 **#Vide g. 104. 



