African P/debotoinic Diplera. 22.'i 



6 to 7 mm. ; width of front at vertex 0'6 mm. to just under 

 1 mm. ; length of wing 14 to 17 ram. 



Seal-brown ; longitudinal stripes on dorsum of thorax and 

 a median series of very broad truncated triangles on abdomi- 

 nal segments grey or smoke-grey ; wings with extreme base, 

 costal border as far as end of first longitudinal vein, and base 

 of anal cell dark brown ; veins in proximal two-thirds of wing 

 distinctly suffused with brown. 



Head: front, face, and jowls grey pollinose; subeulhis 

 cream-buff pollinose; face and jowds clothed with whitish 

 hair ; sides of front only slightly convergent below; frontal 

 callus and its linear extension (when visilde) chestnut, callus 

 elongate quadrate, rounded above, touching or but narrowly 

 separated from the eye on each side ; ocellar region slightly 

 l)rownish ; eyes bare ; palpi tapering to a point, clothed 

 with pale yellowish hairs, sometimes thickly interspersed 

 with black hairs on outer side ; first joiut of antenna pollinose 

 rufous, its upper angle blackish brown, second joint dark 

 brown, third joint black or l)lackish brown. Thorax : pectus, 

 pleurae, a broad ill-defined stripe above base of wings, and 

 three sharply marked dorsal stripes, the median one very 

 narrow and scarcely extending beyond middle, grey ; a stripe 

 of black hair in front of base of wing ; postalar callus 

 bearing a conspicuous tuft of whitish hair ; grey dorsal 

 stripes clothed with yellowish hair, dorsum elsewhere 

 clothed with dark brown or blackish hair, pectus and pleurse 

 with whitish hair ; scutellum grey pollinose, ground-colour 

 ferruginous, brownish at base, clothed at base and on disk 

 with dark brown hair, margin fringed with whitish hair. 

 Abdomen : median series of very broad, truncated, smoke- 

 grey triangles on dorsum very conspicuous and sharply 

 defined, forming a continuous series extending from the 

 second to filth segment inclusive; on the first segment 

 there is merely a median grey spot, in contact with the 

 truncated apex of the triangle on the second segment ; on 

 the second, third, and fourth segments the broad bases of 

 the triangles, which rest on the hind margin, extend on each 

 side considerably beyond the truncated apex of the following 

 triangle ; a median grey mark sometimes visible on sixth 

 segment ; second, third, and fourth segments with a small, 

 somewhat oval, grey spot on each side of the median 

 triangle, and much less pronounced than the latter ; first 

 segment lightly greyish polliuose when viewed obliquely 

 from l)ehind ; triangles elothcil with minute pale yellowisli 

 iiairs ; lateral margins of segments clothed with whitish 

 hair; venter greyish pollinose, clothed with minute pale 



