A Monograph of Egyptian Dtps era. 103 



2. S. SUBTILIS BECK. (PI. VI, fig. 2). 



Beck., Mitteil. Zool. Mus. Berl., II. 89.125. (19 



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

 veins; hind femora without any strong basal spine; antennae 

 entirely yellow. 



DESCRIPTION:— Male: Very similar to the preceeding 

 species, but easily distinguished from it by the following charac- 

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

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

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

 Vertex shining black with two roundish spots of greyish-yellow 

 dust on the base and sides of the front ocellus. The pubesc 

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

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

 the sides of the thorax, which extern is from the humeri to the 

 sutures, is ochraceous. 



Thq second segment of the abdomen has the markings prac- 

 tically identical with those of the corresponding segment of the 

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

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

 its sides yellow and possesses a dull 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 b 

 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 basal corners are less broadly 

 greyish. Venter rather opaque. Hypopygium with the lamella not 

 possessing any tufts of erect bristles. The colour of the leg 

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



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

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

 spines on the basal 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 extreme bases of the veins, th< i and 



the subcostal cell, are yellowish. 



Female: Very similar to the male but the cenl i 

 black band on the third segment reaches the basal and the 



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