1. THEREVA 569 



with numerous black hairs intermingled on the middle of the face and on 

 the jowls. Female with a small narrow frontal callus; abdomen with 

 whitish hindmargins of segments. 



The male is the blackest of our British species. - 



A This description has been made from a specimen which was caught by 

 Colonel Yerbury at Lyndhurst in the New Forest on June 16, 1897, but as 

 it is partly discolored through grease I have eked out the descriptipn by the 

 help of a male from Kowarz's collection which was taken at Marienbad on 



July 20, 1869. , . . , , . . , . ,, 



Face ashy yellowish grey, but slightly whitish shimmering about the 

 lower part and round under the eyes ; frons more greyish tawny dusted but 

 narrowly blackened at the sides down to the level of the antennae (perhaps 

 discolored) ; pubescence on the frons forming a rather dense black tutt, and 

 similar pubescence extends broadly down the sides of the tace and is but 

 little reduced until well round the lowest part of the eyes and even atter 

 that numerous black hairs are intermixed with the dense brownish yellow 

 pubescence on the lower part of the back of the head ; pubescence on the 

 middle part of the face brownish yellow and slightly drooping but with more 

 suberect long black hairs intermixed than in any other British species, and 

 similar brownish yellow pubescence extends rather inconspicuously all round 

 the antenncB ; the mixed pubescence on the jowls amalgamates with similar 

 pubescence on the front coxai ; close against the lower part ot the back ot 

 the eyes is a patch of shorter all pale pubescence, and the pubescence on the 

 upper part of the back of the head is shorter and denser but darker brownish 

 orange : the usual black postocular fringe of curved and slightly overhang- 

 ing hairs begins rather sparsely and rather short at about the middle ot 

 the back of the head but soon becomes dense' and long and merges 

 into the shorter thinner black hairs on the vertex ; the usual strong black 

 bristles quite out on the back of the head are barely perceptible -vertex 

 covered with greyish orange dust ; proboscis brown. Eyes touching tor less 

 than one-third the distance between the occiput and the antennae but 

 the part of contact nearer to the occiput than to the antennai ; tacets 

 fairly large on the upper part but steadily though almost imperceptibly 

 diminishing in size to the lower part. Antenna yellowish grey on the basal 

 joint but greyer on the second joint, and dull brown (except for its obviously 

 ferruginous base) on the third joint ; basal joint with the usual hair-like 

 pubescence on its basal half which is partly black but with long pale hairs 

 " beneath near the base, and with the usual stiff black bristles on the apica halt ; 

 second joint with the usual numerous short black bristly hairs; third pint 

 with two or three tiny black dorsal bristles near the base ; style angulated 

 from the third joint, and with a distinct though tmy apical arista. 



Thorax blackish (probably from discoloration, or else_ probably greyish 

 brownish black with two faint paler stripes and the hindmargin paler) : 

 pleurae ashy grey. Pubescence suberect, composed of predominant ratter 

 long black hairs with some short inconspicuous yellowish brown hairs inter- 

 mixed on the disc, but with abundant yellowish brown hairs on the sides and 

 hind part amongst which a few inconspicuous black hairs are intermixed ; 

 pleurtB with pale greyish yellow pubescence, but with numerous black hairs 

 intermixed in the large mesopleural tuft and with some on the hind part ot 

 the metapleural tuft; chtetotactic bristles almost as m fig. 3}1 but rattier 

 difficult to trace in the long dense black pubescence, two with perhaps a 

 smaller thinner one on the postalar cadi. Scutellum greyish orange about the 

 margin, mainly clothed with moderate fine yellowish brown pubescence but 

 with some considerably longer weak black hairs on the disc. 



Abdomen discolored in the specimen described but probably blackish 

 with obscure indefinite brownish bands before the pale hnidmargmal hems 

 and with these bands becoming broadly greyish black and more obvious about 

 the sides of the two basal segments ; hindmargmal hems dark_ orange, con- 

 spicuous on the second to seventh segments but steaddy growing narrower 



