270 [DfCfmber, 



diy specimen. In addition there is a black, highly chitiniscd structure 

 at the base of each side piece ; the structure is split into two curved 

 branches, one o£ which is sharp pointed, the other rounded at the tip. 

 The clasper is rather blunt-ended. The folloAving material is before 

 me:— Stoke Wood, Hereford {Wood); Boyton, Suffolk (Vermll) ; 

 Llangollen (F. W. E.). 



J), mihilipennis Curt. — According to Curtis this differs from 

 D. nebulosa in that "the 2 central black lines on the thorax are mucli 

 longer, and the clouds on the wings are much less distinct." This 

 reference to fioo black central lines would seem to exclude the last foiu- 

 species, and if Curtis's specimen was not a pale D. nebulosa, it must 

 have been the species for which I now propose to use the name. 1 should 

 have preferred to call it D. sithnehiiJosa Strobl (described as a variety of 

 D. maculata), had not Strobl stated that the central thoracic stripe was 

 simple, as in the typical form. By colour characters this species falls 

 with D. nchidosa, from which it is at once separated by the unmarked 

 fork-cells. The hypopygial structure, however, would place it mvich 

 nearer to D. maculata than to D. nebulosa. The ninth tergite is armed 

 in the same way, and there is a short, thick, curved, black spine on the 

 inner side of the side piece towards the base ; in D. nubilipennis, 

 however, this spine is simple instead of forked. I have taken the 

 species commonly at Dartmouth, S. Devon, and Radwell, Herts ; 

 the National collection also contains examples from Sheviock and Tor- 

 cross (Yerburf/) and Ugbrooke (Verrall ; determined as D. nebulosa). 



D. nebulosa Mg. — This species needs no further elucidation, as it 

 is readily separable from the others by the more elaborate clouding of 

 the wings. The hypopygium resembles, without being identical with, 

 that of D. dilatata. I have taken it at Waterford, Herts (abundantl}'), 

 and Dartmouth, S. Devon, and there are various other specimens in the 

 British Museum. It is no doubt common and widely spread. 



British IMiiseum (Nat. Hist.), Loudon. 

 October Uth, 1920. 



THE BRITISH SPECIES OF THE SFLT^JTICfW-GEOUP OF 

 PIPUNCULUS (DIPTERA 



BT J. E. COLLIN, F.E.S. 



A revision of the work on this genus published by the late 

 Mr. Verrall in his " British Flies," vol. viii, has become necessary as 

 the result of an examination of a considerable amount of material 



