20 SYBPHIDJE. 



black, unspotted ; hind femora with 

 a black ring, hind tibiae sometimes 

 entirely black ; hind tarsi wholly 



black or with pale base var. mauritianum, Big. 



12 (5) Leg8 mainly black, the front femora 

 black at the base, the trochanters 

 black, the hind legs wholly black 

 or only with pale knees ; antennae 

 almost entirely black ; second abdo- 

 minal segment usually unspotted ; 

 wings more or less infuscated .... infuscatuin, Beck. 



10. Melanostoma "bituberculatum, Loew (1857). 



Allied to scalare, but at once distinguished by its double facial 

 tubercle. 



It is worthy of note that Adams redescribed the present species 

 as new in 1905, under the name given to it by Loew in 1857; he 

 was misled perhaps by the fact that Loew placed his species under 

 Syrphus. 



Typical examples have the antennae almost entirely and the 

 legs entirely yellow ; but there are specimens with very dark 

 antennae and with darkened hind legs, or even with all the femora 

 blackened. 



A typical couple from Durban (F. Mitir) ; a male from Njaro, 

 Brit. E. Africa (A. J. Cholmley), in which the yellow spots on 

 third and fourth abdominal segments are fused together, forming a 

 broad transverse band ; the abdomen is therefore wholly yellow, 

 only the base and two narrow transverse lines being black. A 

 male and two females with darkened antennae and legs from Brit. 

 E. Africa, E. side of the Aberdare Mountains, 7,300 ft., 24. ii. 1911 

 (T. J. Anderson). 



11. Melanostoma floripsta, Speiser (1910). 



A species distinguished by its comparatively large size, entirely 

 yellow legs, very broad rectangular yellow abdominal spots, and 

 infuscated wings. 



This spacies is not closely allied to the following one, but has 

 some resemblance to a Platychirus, as stated by Dr. Speiser. Ori- 

 ginally described from Kilimandjaro and Meru ; there is a single 

 female specimen from British E. Africa, M'bagori's Village, edge 

 of Kenia Forest, 5,000 ft., 12. ii. 1911 (T. J. Anderson). 



12. Melanostoma scalare, Fabricius (1794). 



A well-known European species, characterised by its slightly 

 pubescent arista, the narrow abdomen of the male, the triangular 

 yellow rather long abdominal spots of the female, and the absence 

 of black rings on the legs. 



Two females from Mt. Chirinda, S. Rhodesia, vi. 1911 (C. F. M. 

 Swynnertori) ; Dr. Speiser received the species from Kilimandjaro. 



