African Species of the Genus Chrysops. ol9 



blackish brown and clotlicd with Ijrownish hair ; antcnn(B 

 (tliird joint missing) Ijhick, not slender, first joint slightly 

 incrassate and also somewhat elongate, length of second joint 

 two thirds of that ol' first joint ; hair clothing first and second 

 joints black. Thorax : black stripes on dorsum at least 

 twice as broad as the pai^' of yellow stripes separating them, 

 which are somewhat paler than elsewhere ; a dark brown 

 stripe on side of thorax on a level with base of wing, extending 

 from front margin to postalar callus ; beneath this stripe in 

 well-preserved specimens there is a thick fringe of cadmium- 

 yellow hair, and the lateral yellow stripe external to the 

 outer dorsal black stripe bears similar hair ; lower part of 

 mesopleura and pectus blackish brown. Scnfellum yellow on 

 sides and posteriorly; end of median thoracic stripe forming 

 a dark shield-shaped median spot, not extending to hind 

 margin ; yellow area on scutellum and admedian yellow thoracic 

 stripes apparently pollinose, the ground-colour being black. 

 Abdomen : black dorsal stripes starting from a common 

 base on front margin of first segment beneath scutellum, 

 dividing just before reaching liind margin of this segment, 

 and extending Avithout interruption to the seventh segment ; 

 they approach one another on the sixth segment and almost 

 or quite come into contact on the seventh ; on the third and 

 following segments the stripes widen out so as to reach the 

 lateral margins ; venter, except a scarcely visible black or 

 blackish median area at extreme base on first segment, 

 entirely cadmium-yellow without markings, clothed with 

 short, appressed, similarly coloured hair; median dorsal 

 stripe and sides of first and second segments clothed with 

 similar hair. Wings : transverse band extending to hind 

 margin (though lighter posteriorly), and so broad that wing 

 may be described as blackish brown with exception of a large, 

 semihyalinc, triangular area at the base ; the upper margin of 

 this light area, which is somewhat blurred, starts at the base 

 of the anal cell and runs obliquely forward into the marginal 

 cell a little before the base of the third longitudinal vein ; 

 the anterior side of the light area is formed by the proximal 

 margin of the transverse band, which runs at right angles to 

 the costa, from the base of the third vein straight down into 

 the anal cell; the alula, axillary cell, and apical portion of 

 anal cell are all infuscated ; lighter area in distal lialf of 

 wing widest in first submarginal cell (/. e. below what in the 

 case of other species would be the apical blotch), and thence 

 progressively diminishing in width. Halteres (lark brown. 

 Legs entirely black and clothed with short black hair, none 

 of the tibiai incrassatcd. 



