A Monograph of Egyptian Di fiera. 103 



■2. S. SUBTILIS IJECK. (PI. VI. fio-. 2). 



Beck., Mitteil. Zool. Mus. Berl., II. 89.125. (1903). 



DIA GNOSIS: — Vena spuria distinct and black like tlie other 

 veins; hind femora without any .strong basai spine; antennas 

 entirely yellow. 



DESCRIPTION:— Maie: Very similar to the preceeding 

 species, but easily distinguisbed froni it by the following charac- 

 teristics, the gênerai colour of the dust and hairs on the face and 

 f rons which is greyish-yellow, and by the markings of the abdomen 

 which are very similar to those of the female of S. sfinkjera. 

 Vertex shining black with two roundish spots of greyish-yellow 

 dust on the base and sides of the front oceUus. The pubescenoe 

 on the thorax is much shorter than in S. spinigera, being hardly 

 perceptible with a strong hand lens, and the colour of the dust on 

 the sides of the thorax, which extends from the humeri to the 

 sutures, is ochraceous. 



Thq second segment of the abdomen bas the markings prae- 

 tically identical with those of the corresponding segment of the 

 female of S. spinigera, but hère the whitish colour on the discal 

 ends of the yellow markings is absent. The third segment also bas 

 its sides yellow and possesses a dnll black band on its lower 

 margin, the depth of which is equal to about one third the length 

 of the segment ; in addition, the central black longitudinal line 

 joins the band on the lower margin, but ends well before the basai 

 margin, so that the two large yellow side margins meet above ; the 

 lower margin of this segment is similar to the corresponding one 

 in the preceeding species, but its basai corners are less broadly 

 greyish. Venter rather opaque. Hypopygium with the lamella not 

 possessing any tufts of erect bristles. The colour of the legs is 

 very much like that of S. spinigera but the hind metatarsi are 

 rather darkened above; the hind femora do not possess the strong 

 basai spine below, but only a row of four or five much smaller 

 spines on the basai half ; the apical third of the hind femora is 

 deeply serrated below as in the preceding species. 



Wings pellucid, with the vena spuria as black and as distinct 

 as the other veins ; the extrême bases of the veins, the stigma and 

 the subcostal cell, are yellcnvish. 



Female: Very similar to the maie but the central longitudinal 

 black band on the third segment reaches the basai margin, and the 



