Aphiochaeta. 



329 



thick veins brown or blackish, the thin veins fine and pale; siibcostal 

 vein rather curved and hence the costal cell somewhat deep; costa 

 short, about 0,38 of the wing-length, costal divisions a little varying, 

 but generally about as 4 — 1 — 1, but the first division may be relatively 

 a little shorter; costal cilia long; the anterior branch of the fork 



Fig. 101. Wing oi A. pus illa S. 



somewhat thin, but the posterior thick; fourth vein slightly curved 

 at its origin, for the rest nearly straight. H alteres black. 



Female. Similar to the male, only the hind tibiæ and metatarsi 

 a little less dilated. 



Length 1 — 1,4 mm, 



This species will generally be known without difficulty, but it 

 varies to some degree; the variation concerns the length of the costa 

 and of the costal divisions, also the costal cilia vary a little in length; 

 further the degree of thickening of hind metatarsus is various and the 

 front tarsi are generally slightly thickened, but sometimes appear 

 more conspicuously thickened; the hypopygium on the other hånd 

 is always of the same construction. 



A. pusilla is common in Denmark; Copenhagen, Ermelund, Lyng- 

 by, Holte, Geel Skov, Hillerød, Alindelille and Suserup Skov at Sorø, 

 Bogø south of Sealand, Lohals on Langeland and in Jutland at Hejls 

 south of Kolding, Ry and Jelling (Th. Mortensen, the author); the 

 dates are V5 — ^7ii in 1916 to 1921. I have taken it in copula on ^U. 

 Four of my specimens, two males and two females (from Bogø) have 

 yellow or dusky yellow palpi and also paler legs, but otherwise agree 

 in all respects; they answer perhaps to the var. mentioned by Wood 

 (1. c. 201), but, as far as I see, the hypopygium shows no difference. 



Geographical distribution : — The species is common and widely 

 distributed; Europe and down into North Africa; it does not seem to 

 occur north of Denmark, or is at all events not recorded from the north; 

 it is also recorded to occur in Australia, but with some doubt. 



