African Species of the Genus Chrysops. 517 



under surface of head thinly clothed with rather lon^ and 

 fine yellowish hair, longer below ; 2}a/pi blackish, slender or 

 of medium thickness, clothed with minute yellowish liairs ; 

 antennae not elongated, first joint more or less incrassated, 

 second joint two thirds of length of first ; first and second 

 joints dark mouse-grey, somewhat shining, clothed with 

 rough-looking yellowish-brown hair ; last joint dull brownish 

 black. Thorax : dorsum with a pair of well-defined, broad, 

 shining, blackish-brown longitudinal stripes, rounded off at 

 each end, but not interrupted on transverse suture ; these 

 stripes se})arated by abroad median mouse-grey stripe, darker 

 from front margin to a little beyond transverse suture, the 

 darker portion with a light grey edging ; pleurae yellowish 

 poliinose (lower portion of mesopleura blackish), with thick 

 tufts of cadmium-yellow hair ; dorsum clothed with fine, 

 erect, pale yellow hair; scutellum dark mouse-grey, clothed 

 with long, thin, yellowish hair. Abdomen : ground-colour 

 of dorsum olive-grey, sides of first and second segments 

 sometimes ochraceous ; first segment with a blackish-brown 

 median blotch, extending well beyond scutellum on each 

 side; paired blotches on the four following segments roughly 

 triangular in shape, rounded oft' behind, and not extending 

 to hind margins, but sometimes transversely elongate, being 

 produced so as to include basal angles of segments ; sixth 

 and seventh segments mouse-grey ; dorsum (except on black 

 blotches, which are covered with minute, appressed, blackish 

 hairs) clothed with short chrome-yellow hair, most noticeable 

 on hind margins of segments ; sides of segments, from first 

 to fifth inclusive, fringed with bright cadmium-yellow hair ; 

 venter yellowish grey, clothed T»ith cadmium-yellow hair, 

 basal portion of some of the segments sometimes with dark 

 brown transverse bands. Wings : basal brown area in first 

 basal cell includes the proximal two thirds ; in second basal 

 cell it may be confined to proximal third, or, if extending as 

 far as in first basal cell, may be more or less obliterated 

 posteriorly ; proximal margin of transverse band running 

 perfectly straight from base of third vein to inner basal angle 

 of fifth posterior cell, thus filling out the tips of the first and 

 second basal cells with colour; distal margin of transverse 

 band commencing at end of second longitudinal vein and 

 running obliquely backwards so as to include basal half of 

 fifth ])ostcrior cell ; distal margin of transverse band with 

 three indentations, the first in first submarginal cell, above 

 fork of third vein, the second in first posterior cell, and the 

 third on or near vein separating fourth and fifth posterior 

 cells ; the transverse band dies uway in the anal cell; trans- 



