1020.] 269 



ill the wings. Wlien tliese are viewed through a lens at a very ohliqiie 

 angle, a whitish patch a})i)ears in cell cUj, as well as in cells in and cii,. 

 On the average, the species seems to be smaller than the others of this 

 group. A specimen in the Verrall collection from Loch Maree was 

 named D. maculata ; other examples in the British Museum are from 

 Loch Assynt, Sutherland, and Aviemore, Inverness {Yerhtiry) ; Bonawe, 

 Argyll ( Waterston ) ; also Dartmouth ; Snailbeach, Salop ; Llandwrog, 

 Carnarvon; Brodick, Arran ; and Burnham Beeches, Bucks {F. W. E.). 



D. suhmaciilafa, sp. n. — This should be readily distinguishable from 

 all except D. maculata by the characters given in the key ; in addition, 

 it may be noted that it differs from both D. maculata and D. dilatata 

 in having no trace of whitish coloration in cell cu^, when the wing is 

 viewed obliquely. The tips of the femora are more distinctly black, 

 and the remainder of the femora more distinctly yellow in this and 

 D. maculata than they are in D. puherida and D. dilatata. The 

 hypopygium has much resemblance to D. fulerula and I), dilatata, but 

 besides other good specific differences in the anal and genital parts, the 

 elasper is of a different shape, tapering to a rather long, sharp point 

 which faces inwards. The ninth tergite is simple. In the wings the 

 basal section of R.1+5 is not much shorter than the r-m cross-vein — a 

 point in which this species resembles D. maculata, but differs from 

 B. imhei-ula and D. dilatata, which both have the basal section of 

 R4+5 very much reduced or even absent (that is to say, in this last 

 case, the r-m cross-vein is situated exactly at the apex of Us). The 

 British Museum collection contains the following material : — Rugby 

 {Austen); Symondsbury, J)ov?.Qi {Eaton) ; Sheviock, Cornwall {Ter- 

 hury) ; Hatch End, Middlesex ; Letchworth, Herts ; and Snailbeach, 

 Salop {F. W.E.). 



D. maculata Mg. — I accept Loew's suggestion that Meigen intended 

 to describe two dark spots on the scutellum rather than before it. I 

 have no doubt that I have Loew's D. maculata before me, and as he 

 was the " first reviser " of Meigen's species, it will be well to follow him 

 in his use of the name ; though, as noted above, it is just possible that 

 Meigen's D. maculata may have been D. aestivalis. D. maculata 

 (Mg.) Lw. may be recognised without much difficulty by the characters 

 given in the key and in the notes on the preceding species. The dark 

 sides of the scutellum are conspicuous in all the specimens examined, but 

 may not always serve to separate it from D. submaculatn. In the 

 structure of the hypopygium, however, it is very different from B. sub- 

 maculata and more like B. nuhilipennis. The chief peculiarity is the 

 presence of a long, strong, curved spine at each apical corner of 

 the ninth tergite ; these spines are usually plainly visible even in the 



