274 [December, 



Grermar's from Paris, while Eondaui found it at Parina in Italy, and 

 this latter comitry appears to be the only one in which it has been 

 taken in any numbers. — J. E. C. 



TWO DIPTERA NEW TO BRITAIN. 

 BY D. SHARP, M.A., F.R.S. 



1. MiCRODON EGGERI, Milv. 



This species is readily distinguished from its three British 

 congeners by its dark scutellum, short antennae, and strongly clouded 

 wing-nervures. 



It is the M. brevicornis of Egger ; Mik proposed the new name 

 for it (Wien. ent. Zeit., xvi, 1897, p. 66) on account of brevicornis 

 being already in use for an African species. 



I captured a single specimen of M. eggeri at Eannoch early in 

 June this year, settling in the sunshine on a birch log. 



According to Mik there are very few records of the occurrence of 

 this insect ; indeed he says (Wien. ent. Zeit., xviii, p. 138) that it is 

 the rarest of the European species, and that he knew only of two 

 records of its occurrence, to which he adds a third, all these being 

 from Austria. Since then, however, Wasmann has informed us that 

 the larva of M. eggeri is not uncommon in the nests of Formica 

 sanguinea in the Luxemburg. I am sorry that I forget from which 

 one of Wasmami's numerous and valuable memoirs I derived this 

 information. 



M. eggeri is the fourth British member of this interesting genus, 

 and as we have now all the four known European species of Microdon 

 no other addition is to be expected to our list. 



2. ErNONEURA ARGUS, Zett. 



This is the only species of the genus, and is therefore a generic 

 addition to the British Catalogue. 



E. argus is a remarkable Scatomyzid form, distinguished from all 

 others by the extremely peculiar coloration of the wings, which have 

 nimierous dark round marlcs, the small nervures being broken in a 

 correlative manner. 



I captured a single example of this species on the shores of Loch 

 Garten, near Nethy Bridge, in the latter part of June or early July, 

 three or four years ago. This is not, however, the first time the 

 insect has occurred in Britain, as previously Colonel Yerbury captured 

 a specimen in the Thurso district on the shores of a small loch near 



