30 F. W. EDWARDS. 



under which it is sunk in the Catalogue of Palaearctic Diptera. I also consider 

 that S. auricoma and S. fasciata of Meigen, and S. crassitarsis of Macquart are really 

 only S. ornatum, though S. auricoyna appears as a synonym of S. latipes in the 

 Palaearctic Catalogue. Curtis' S. trifasciatum is undoubtedly a synonym, and 

 Macquart's S. tihiale and S. vernum may perhaps be others. Lundstrom, believing 

 the genitalia to be variable, described the species as a variety of S. reptans, but the 

 two are perfectly distinct, even Meigen having appreciated some of the differences 

 between them. 



2. Simulium variegatum, Mg. (figs. 1,3). 



Closely allied to S. ornatum, but differs in the following particulars : — Front tarsi 

 (fig. 3, h) in both sexes markedly longer and thinner ; no sign of soft hairs on the pleurae 

 between the prothoracic stigma and the base of the wing ; male genitalia (ten 

 specimens compared) with the adminiculum (fig. 1, h) rather smaller ; legs of female 

 much paler, the front coxae and femora being entirely yellow, and usually the middle 

 femora also, though sometimes these are somewhat darkened towards their tips ; 

 the ground colour of the front tibiae is yellow, except on the apical fourth. These 

 differences, though for the most part slight, are I believe constant. 



Time of appearance. — From 18th April to 20th September. 



Distribution. — Scotland : Gorge of Avon, nr. Hamilton, Lanarks. (K.) ; Cleghorn, 

 Lanarks. (K.) ; Bonhill, Dumbarton (K.) ; Forres (K.) ; Kirkcudbright (K.) ; Comrie 

 and Blairgowrie, Perth {Ct.) ; Nethy Bridge, Spey Bridge, Aviemore, Kincraig, 

 Dunachton and Corrour, Inverness {K., Y., and G.) ; Logic, Elgin (J .) ; Dingwall, 

 Cromarty (K., Y .) ', Loch Assynt, Sutherland (Y.). Ireland: Cappoquin, Co. 

 Waterford {K.) ; Wexford {K.) ; Newcastle, Co. Down {K.). England : Aysgarth 

 Force (G.). 



From the above list of localities it would seem that this species is confined to 

 comparatively high altitudes, where it to a large extent replaces S. ornatum. 



Synonymy. — As Meigen lays stress on the yellow femora I think the species must 

 be correctly identified, though it has not been properly distinguished before. The 

 Palaearctic Catalogue places S. variegatum as a s}nionym of S. reptans, but I cannot 

 accept this, as I have not seen a single specimen of S. reptans with yellow femora. 

 S. varium, Mg., would seem from the description to be S. variegatum. Zetterstedt 

 describes it as S. ornatum var. b, but I think the structural difference in the front 

 tarsi is sufficient to entitle it to specific rank. There is a correctly named specimen 

 in the old British Museum collection, and other specimens in the Stephens collection 

 over the manuscript names affinis and luteicornis ; though these names were listed 

 by Stephens in his catalogue, no description was ever published. 



3. Simulium reptans, L. (figs, l, 3, 4). 

 Length, 2-3-3 mm. 



Male. — Thorax with the silvery markings rather smaller, more rounded and 

 decidedly more brilliant than in S. ornatum, and with the golden pubescence much 

 more scanty. Pleurae without the patch of hairs in front of the wing-base. Abdomen 

 much as in S. ornatum, but less hairy ; the hair on the basal scale black. Genitalia 

 (about a dozen mounts compared ; fig. 1, c) : claspers of slightly different shape from 



