1 q/» [September, 



56 (55) Hind tibife at tip slightly blackish ; basal joint of hind tarsi usually all 



black 35. latilimhatus Macq. 



57 (54) Wings almost hyaline ; hind tibia? entirely yellow ; basal joint of hind 



tarsi usually to some extent pale at base ...36. andalusiacus Strobl 



58 (53) Face without any distinct pubescence ; autennoB with at least tip of under- 



side of basal joint ochreous. 



59(60) Hind coxa3 entirely yellow ; hind tibiER black at tip... 



30. acxdicornis Wied. 



60 (59) Hind coxte mainly grey. 



61 (62) Basal joint of middle tarsi, and even tip of middle tibite, black... 



37. medlicoriiis Verr.* 



62 (61) Basal joint of middle tarsi pale at base. 



63 (64) Hind tibiae conspicuously blackened at tip 32. puncticornis Zett. 



64 (63) Hind tibise quite pale, or only slightly darkened at tip. 



65 (66) Hind tibiae obscured at tip ; middle tibise with 5-6 bristles in front... 



19. signattis Meig. 



66 (65) Hind tibife yellow to absolute tip ; middle tibite with 3-4 bristles in 



front 17- ■pennatu.i Meig. 



67 (52) Antenna; with more than under-side of basal joint, and base of under-side 



of second joint, pale. 



68 (71) Third joint of antenna; all black. 



69 (70) Hind coxfe pale yellow 33. UnearisMeig. 



70 (69) Hind coxa; grey 40. simplex Meig. 



71 (68) Third joint of antenna; partly yellow. 



72 (73) Squamae with yellow fringes 39. strigipes Verr. 



73 (72) Squamte with black fringes. 



74 (77) Basal joint of antenna; all yellow. 



75 (76) Hind tibise black at tip 15. ^Zz<mi>e« Scop. 



76(75) Hind tibise at tip and base of hind tarsi pale 16. Wahl be rg i Zelt. 



77 (74) Basal joint of antennae blackened above. 



78 (79) Hind coxa; mainly pale yellow ; hind tibise all yellow... 



31. longicornis Stann. 



79 (78) Hind coxa; mainly grey 29. sahimts YiuX. 



80 (23) Lower postocular cilia black. 



81 (82) Hind femora with more than one preapical bristle 41. imgulatus L. 



(= seneus De G.) 



82 (81) Hind femora with only one preapical bristle. 



83(84) Basal joint of middle tarsi with a strong bristle above... 



43. hrevipennis Meig. 



84 (83) Basal joint of middle tarsi without a strong bristle above. 



85 (86) Face whitish, frons green 42. longif arsis Stann. 



(= equestris Hal.) 



86 (85) Face and frons greyish 44. rupestris R&l. 



1. ID. atratus Meig. : common throughout Britain in forest or marshy 



districts, usually on alders by the side of streams. A closely 

 allied species, D. macuUpcnnis Zett., with two pre-apical 

 spines on the posterior femora ought to occur in Scotland. 



• D Hneaticornia, Zett., Is omitted, as the female i.s unknown ; it is probably very nidch like 

 J), mediicornis, Verr., but larger, and with stronger bristles on the tibise. 



