H. C. EFFLATOUN. 



ERISTALIN.E 



Antennse moderate in shape and length, dronping; arista 

 dorsal and always bare in the Egyptian species. 



Wings with the radio-median cross-vein at, or after, the 

 middle of cell M2; Radius 4 + 5 with a deep siulden loop down- 

 wards at about the middle of cell R5; cell RI either closed or 

 open. Legs usually simple, but the hind femora sometimes thicke- 

 ned and curved, with a dilatation just before the apex. 



Many of the members of this sub-family (especially the Euro- 

 pean and Exotic gênera) seem to mimie bées and ail may be k'nown 

 by the peculiar loop in the cubital vein. The métamorphoses of 

 many European species hâve been studied and nearly ail approx- 

 I iiaie to the well known "rat-tailed" larva of Eristalis tenax. 

 Thèse live in liquid mud or filth and the long anal process can be 

 extendod or diminished by the larva according to the varying 

 depth of the liquid in which it exists. I hâve found the larvse of 

 Eristalis in varions stagnant ponds near Cairo in company with 

 the rathcr familiar and similar larva of Hirtea nnubis (Stratio- 

 miid.ie). 



I havc also watched the adults of E. tœniops and œneus 

 hovering and resting over the edgcs of thèse ponds and in ail 

 probability they were ovipositing. I bave further found larvœ of 

 Eristalis in a water tank containing macerated bones, at the 

 School of Medicine, in conjunction with Psychodid and_ Culicid 

 larvœ and bave watched the femalc of E. tœniops hovering over 

 this tank and ovii)ositiiig in the moist chinks and cracks of the 

 floating bones. 



The only représentatives of tiiis sub-family in Egypt belong 

 to the two great gênera Eristalis and Ildofhilus which contain 

 most of the species and which are represented ail over the world. 

 Howcver the truc llelophilus does not seem to bo represented hère 

 (nor apparcntly in Nor'tli Africa) but those tliat do occur belong 

 mniiily to the Sub-Gernis Mcscnthrins. 



