340 TABANIDiE 



are Avhitisli grey but vary in narrowness and sharpness of definition, 

 being most sharply and conspicuously defined when the abdomen is mainly 

 dark brown black. Pubescence short depressed and_ black on the disc, but 

 the fringes on the sides of the hindmargins pale (distinctly so on only the 

 three basal segments), and all the pubescence widely on the sides of the two 

 basal segments longer more erect and conspicuously whitish, while this whitish 

 pubescence extends (though shorter and more sloping) down the sidemargins 

 of the third and fourth segments except that sometimes parts of the side- 

 margins of the fourth to sixth segments have black hairs ; on the other hand 

 sometimes all the marginal pubescence is whitish, or the hindmargins of the 

 sixth and seventh segments may bear inconspicuous brownish orange 

 pubescence. Belly dusted pale ashy grey (when seen from the base) on a 

 blackish ground colour, but more blackish on the last three segments and 

 with no dark middle stripe ; pubescence moderately long and abundant, 

 sometimes all whitish except beneath the seventh segment, but more 

 commonly black on the disc of the last three segments, though sometimes 

 yellowish on the third and fourth segments, and sometimes brownish orange 

 about the sides and hindmargins of the last three segments. 



Legs colored as in the male but less pubescent, shorter and thicker 

 (especially the hind tibiae) than in //. phivialis. _ Pubescence more_ extensive 

 than in 11. pluvialis ; front coxae with long white pubescence quite to the 

 tip ; front femora with a fair amount of pale pubescence on the basal half, 

 which grows to black behind the apical half ; pubescence more abundant than 

 in //. pluvialis on the posterior femora and pale with only a few black bristly 

 hairs at just the tip ; " touch-hairs " on front legs shorter than in //. pluvialis. 



Wings, squamse, and halteres very similar to those of the male, but the 

 wings slightly lighter colored ; knob of the halteres light brown (but by no 

 means whitish) on the top. 



Length about 9 mm. Austen says 8-11 mm. 



This species is very closely allied to the others, but may be distinguished 

 by its more darkly marmorated wings, shorter antennse of which the basal 

 joint is more incrassate and more extensively shining black and the third 

 joint entirely dull black, by the absence of ferruginous markings at the 

 sides of the abdomen in the male, by the less separated light ocelli in the 

 discal cell, Ijy paler pubescence immediately behind the vertex in the 

 male, and by its generally blacker hue. It varies in the distinctness of 

 the light grey markings on the thorax and abdomen, but not in such a 

 manner as to confuse it with its allies. 



H. crassicornis was common at Eannoch in June 1870, and had obviously 

 been taken there in July 1825 by Messrs Duncan and J. C. Dale. I 

 have other records from Hampshire (New Forest), Sussex (Blackboys), Kent 

 (Abbey Wood), Surrey (Camberwell), Cambridgeshire (Wicken and Wisbech), 

 Suffolk {t. 0. Morley), Norfolk (Brandon and Hunstanton), Herefordshire 

 (Tarrington), Cumberland (Buttermere), Glamorgan (Porthcawl), Bute 

 (Arran), Perth (Aberfoyle), Inverness (Nefchy Bridge), Sutherland (Inchna- 

 damph), and Co. Cork (Glengariff). It therefore probably occurs almost 

 anywhere but no doubt has been mistaken for H. pluvialis, and I know that 

 both species may occur in the same districts as I have met with both in the 

 New Forest (near which also H. italica has occurred), in the Isle of Arran, 

 and at Inchnadamph. My records extend from June 5 to August 14, and 

 I believe the males appear before the females, as Colonel Yerbury caught 

 some males at Porthcawl as early as June 5 and Mr C. J. Wainwright 

 took three males at Brockenhurst on June 12, while my earliest dates for 

 females are usually in July, though I caught one in Arran on June 15. 

 Austen (" British Blood-Sucking Flies ") extends its distribution to South 

 Devon, Banffshire, and Co. Galway, and also records a specimen taken as 



