280 EKNEST E. AUSTEN — NEW AFRICAN 



a narrow, ochraceous", lateral edging to anterior two-thirds of second segment, 

 uniformly shining black and clothed with black hairs ; hind margins of ventral 

 scutes of second to sixth segments inclusive whitish grey, and clothed with 

 silvery-white hairs. Winys hyaline, strongly marked with clove-brown or 

 blackish brown, as shown in fig. 1, except that (at least in the case of the three 

 specimens available for examination) the clear spaces in the first and second 

 basal cells are a little smaller than would be supposed from the figure ; trans- 

 verse band, which covers discal cell, extending right across wing, as in T. 

 africanus (not abbreviated before reaching hind margin as in T. latipes), distal 

 margin of band less irregular than in wing of T. africanus ; tip of wing as in 

 T, latipes, i.e. merely with a grey border composed of minute hairs, the tips of 

 the second longitudinal and anterior branch of the third longitudinal veins not, 

 as in T. africanus, suffused with dark brown. Squamae and lialteres as in 

 2\ latipes, though base of knobs and distal extremity of stalks of halteres some- 

 times dark brown. 



Northern Nigeria and Sierra Leone Protectorate : type from 

 Amageddi, R. Benue, Bassa Province, Northern Nigeria, 23. ix. 1909, and a 

 second example from South Boruu, Northern Nigeria, between September and 

 December, 1908 {Dr. II. A. Foy, W.A.M.S.); a third specimen from the vicinity 

 of Wankefu, Karene District, Sierra Leone Protectorate, December, 1909 

 {Dr. J. C. Murphy, W.A.M.S.). 



As will have been gathered from the above description, Tahanus necopinus 

 occupies an intermediate position between T. africanus. Gray, and T. latipes, 

 Macq. (that it is not, however, a mere variety or form of either of these species 

 is proved by, inter alia, the difference in the shape of the third joint of the 

 antennae). These three handsome, tawny-ochraceous species constitute a well- 

 defined group, the members of which, owing to the characteristic pattern of their 

 wing-markings, cannot be confused with any other of their congeners at present 

 known. In tabular form their mutually distinctive characters may be indicated 

 as follows : — 



1. Ventral surface of abdomen (except its basal angles 



and the hind margins of the second to the sixth 



segments inclusive) entirely black ... ... necopinus, Austen. 



Ventral surface of abdomen not entirely black ... 2. 



2. Transverse band on wing reaching hind margin ; 



tips of second longitudinal and of anterior branch 

 of third longitudinal vein infuscated with dark 

 brown ... ... ... ... ... ... africanus. Gray. 



Transverse band on wing not reaching hind margin ; 

 tips of veins mentioned not infuscated with dark 

 brown ... ... ... ... ... ... latipes, Macq. 



* For names and illustrations of colours, srr Ridgway, " A Nomenclature of Colors for 

 Naturalists" (Boston : Little, Brown and Company, 1880). 



