A Monograph of Egyptian Diptera. 91 



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on the thorax and not so erect and consequently the ground colour 

 appears blacker and more shining. 



Legs usually black, with the knees and the basal third of the 

 front and the basal half of the middle tibiae yellow; the base of 

 the middle tarsi is also yellow. Pubescence on the anterior legs 

 fairly abundant, very equal and of a faded yellow colour; on the 

 hind legs the femora bear an abundant tawny pubescence, and 

 beneath, a row of coarse black hairs, while the tibiae bear dark 

 tawny pubescence, with a tuft of coarser black hairs, just after 

 the middle on the under surface; the tibiae are rather compressed 

 about the middle, and somewhat twisted. 



Wings pale brownish on the front half, with a small dark 

 brown spot under the end of the subcostal vein, in which spot there 

 is an indistinct cross-vein. The veinlet after the closed cell Rl 

 is prolonged towards the tip of the wing; Anal 2 much undulated. 

 Squamulas dull pale yellowish, the thoracal pair are large and 

 have dense coarse yellowish fringes; the alar ones are also rather 

 large and have a moderately long, simpler, though denser and 

 coarser fringes. Halteres pale yellow, head of club, brown. 



Female: — Very similar to the male, but the eyes are usually 

 more bare, the broad vertex shining black with black hairs, and 

 separated from the black triangle above the antennas by the union 

 of the dust on the sides of the irons, though in the region of the 

 union the dust gets thinner and in the hollow below the antennae 

 the dust covers both sides of the face; the frons, as a rule, has 

 yellow hairs, but sometimes black, or yellow and black hairs inter- 

 mixed. 



Length from 1G to 18 mm. 



The abdomen varies very considerably in its pale markings and 

 some specimens I possess are entirely black, except for the very 

 thin orange-yellow hind margins of the second and third .segments. 



E. tenax is the largest and most widely distributed 

 species of our Egyptian Syrphidae; it is also fairly common. 

 I possess specimens from Cairo, Alexandria, Mariout, Fayoum, 

 Wadi Hoff, etc. and it will certainly be found in many 

 other localities; my dates extend from January to January of the 

 following year. It is also probably the most widely distributed 

 species of the Syrphidae in the world, and Verrall states that it 

 occurs wherever man has established any system of drainage, 

 whence it is essentially known as the Drain Fly, though from its 

 resemblance to the male of Apis mellifica it is known in England 

 ;i-, the "Drone Fly". It occurs in nearly all Europe, India, China, 

 Japan, Cape of Good Hope, North America, Ethiopian Region 

 and New Zealand. 



