26'5 IMi". C. G. Lamb on Exotic lleloniyzldtej cfcc. 



XX. — Sates on Exotic Heloinvzlclro, Sciomyzldfe, and 

 Psilid^. By C. G. Lamb, Mi^A., B.Sc, Clare College, 

 Cambridge. 



Helomyzidae. 



Helomyza, Fall. 



In the Wiener Ent. Zeit. for 1904 Czerny ciiticiilly 

 examined all the species of this genus up to that date ; since 

 then only about half a dozen species have been added, and 

 hence the task of working out the specimens in the collections 

 was much simplified. There was one well-known species 

 and three new ones, one of the latter being very interesting 

 as departing from the almost universal character of having 

 extra costal bristles. 



Hdomyza 2ncta, Wied. 



S. EhODESIA : Chirinda Forest {G. A. K. Marshall, 

 Camb. Coll.). 



There was a fair series of this handsome insect. It 

 exhibits considerable sexual dimorphism. The sex described 

 is the male, and it has the dorsum elegantly variegated in 

 ochre and dark ochreous grey ; its femora are beautifully 

 and regularly spindle-shaped, the mid pair less so, and they 

 bear long dense hairs below. The female has a quite dark 

 dull brown dorsum and scutellum, which exhibit oidy faint 

 signs of the male marks ; the femora are normal, less haired, 

 and the front ones have an anterior spine row — in fact, the 

 sexual differences in the legs are like those of some Scato- 

 jyhagaa. This type of Helomyzd is devoid of the upper 

 patches carrying the orbital bristle.*, and also of the small 

 ocellar triangle joined to these, which are usual in the Euro- 

 pean forms; it has also pictured wings and swollen and hairy 

 male femora ; this form seems to be typically African. 

 (Speiser^ in his Kilimandjaro-Meru Expedition paper, describes 

 two males of the same facies — //. acroleuca •Aud. 11. lacinata — 

 and the next species also belongs to this section. 



Helomyza tngens, sp. n. 



A single male of the picla group was present ; it is larger 

 and more stoutly built than that species. 



Head (top view) : — Frons and antennae entirely yellow to 

 orange, in front a little darker, with microscopic hairs and 



