38 F. W. EDWARDS. 



are indistinct ; the mention by Linnaeus of the head being white above and below 

 the eyes, together with the legs being black, will definitely exclude all the species of 

 our Group A. Zetterstedt suggested that C. equinus might be the same as S.fuscipes, 

 Fries (which is undoubtedly the species now under consideration), though he does 

 not say he had noticed any connection between S. fuscipes and horses, merely 

 remarking : *' Femina fortiter mordens." 



The species is listed in the Palaearctic Catalogue and in Verrall's List of British 

 Diptera as S. maculatum, Mg., and this is probably correct, in spite of the fact that 

 Meigen described the abdomen as spotted with black, which is not the case in dry 

 specimens. Of the other names which are commonly placed as synonyms of 

 S. maculatum, S. fuscipes, Fries, S. marginatum, Mg., and S. pubiventris, Zett., are- 

 doubtless correctly so given ; but whatever S. columbaschense, Fabr., and S. lineatum, 

 Mg., may be, they are certainly not this species, the former having pale tibiae and 

 tarsi, and the latter having the " hinterleib braim, liinten glanzend,^^ and the " schienen 

 alle weisschillernd.^^ Macquart's S. pubescens and S. cinereum are in all probability 

 our S. equinum. Some of the specimens in the British Museum collection have been 

 determined by Verrall and Roubaud as S. lineatum, Mg. Lundstrom determined 

 the species as S. aureum, Fries, but I feel sure he was wrong in this, since if the 

 hind metatarsi had been pale in Fries' specimens, that author would almost certainly 

 have mentioned the fact. 



9. Simulium latipes, Mg. (figs. 1, 2, 4, 5). 



Length, 2 -3-3 -5 mm. 



Male. — Thorax velvet-black, more or less densely clothed with golden pubescence. 

 Pleurae bare. Abdomen velvet-black, with yellowish hair on the basal segment. 

 Genitalia (fig. 1, m) : side-pieces large ; claspers also large, and with a pecuhar twist, the 

 apical part (bearing as usual one short spine) being truncate and bent inwards (the figure 

 is taken from a mounted specimen, about a dozen of which have been compared) ; 

 in a dry specimen the tip of the clasper is usually not visible in a ventral view. 

 Legs dark brown, tarsi blackish ; the integument uniform in colour, though the front 

 tibiae often appear silvery and the base of the middle and hind tibiae golden-yellow, 

 owing to the colour of the pubescence ; the long hairs, which are fairly numerous on 

 the hind legs, are dark ; hind metatarsi (fig. 4, /) very much flattened, their diameter 

 usually about as great as that of the tibia, though there is some variation in this respect. 

 Wings as in the figure (fig. 5, a), the venation being the same as that of all the other 

 British species, with the exception of >S. hirtipes. H alter es brownish yellow. 



Female. — Head grey, with golden pubescence ; antennae black with the two basal 

 joints reddish. Thorax blackish grey, in perfect specimens densely clothed with 

 coarse bright golden pubescence ; pleurae bare. Abdomen equally densely clothed 

 with similar pubescence ; the integument usually dark, but sometimes reddish, 

 except for the small tergal plates which remain dark. Legs : femora and tibiae dark 

 brown, more or less distinctly paler towards the base, the middle and hind tibiae 

 in the lightest specimens with a dark ring at or near the base ; pubescence golden. 

 Tarsi black ; the hind metatarsi (fig. 4, g) sometimes brownish, very little thickened. 

 Claws (fig. 2, c) with a large blunt tooth projecting from the base. Halter es fighter 

 than in the male. 



