MICHODOX. 123 



clothed with hair. The frons of the male is very narrow, and in 

 both sexes irons and face are comparatively narrow, the face being 

 constricted below. There is a rather pronounced sexual dimor- 

 phism, the female being usually of larger size and differently 

 coloured. 



Some Oriental species also seem to belong to this group, e. g. 

 siinplicicornis, de Meijere, from Java, and grageti, limbinercis, 

 and nocrt-ffiiinert, de Meij., from New Guinea. 



The collection includes specimens of the following species : 



1 (2) Femora black, narrowly yellow at the end 



alone ; the female with deep blue body and 

 strongly infuscated wing-* ; abdomen of 

 the male more or less yellow at the base 

 only Irevicornis, Loe\v. 



2 (1) Femora yellow, more or less black above 



towards the base ; the female with seneous, 

 slightly bluii-h body, and not infuscated 

 wings ; abdomen of the male almost entirely 

 yellow ". lestaceus, Walk. 



130. Microdon brevicornis, Loew (1858). 



A well-known species, originally described from Caffraria, and 

 subsequently recorded from Assinie and Belgian Congo in West 

 Africa, and from Usambara and Kilimandjaro in East Africa. 

 The male, which is very different from the female, has recently been 

 described by Prof. Herve-Bazin in Rev. Zool. Afric. iii. p. 100 

 (1913). 



Two males from Obuasi, Ashanti, W. Africa, 12 & 14. vi. 1907, 

 "caught on leaf" and " on stick on damp path" (Dr. W. M. 

 Graham) \ a female from same locality and collector, 15. vi., 

 " caught in bush " ; two females from Freetown, Sierra Leone, 

 W. Africa, 21. viii. and 12. ix. 1899 (E. E. Austen). 



131. Microdon testaceus, Walker (1857). 



A stout rounded species, in the male sex closely resembling the 

 preceding, but distinguished by the different coloration of the legs 

 and by the very different appearance of the female. 



The specimens before me answer well enough to the short 

 description of Walker, and it seems advisable here to characterise 

 the species more in detail. 



d . Length of the body 7 mm. 



Head nearly spherical, of a shining green a?neous colour ; occiput 

 concave, grey-dusted ; frons relatively very narrow, the inner 

 margins of the eyes angulate and converging a little before the 

 middle of the frons, which at the same point exhibits a deep 

 transverse furrow ; hair on frons and occiput rather long, dark 

 grey ; ocelli widely distant from the vertex, situate almost in the 

 middle of the frons. adjacent to each other, but not in contact ; 



