250 [April, 



10. Syephus plavifrons, sj). n. 



S. Ocidis nudis ; epistomate toto Jlavo-albo ; antennis nigrescentibus ; fronte 

 flava, angulo superiore anguste nigrescente ; thorace ceneo, nitido, scutello pallida, 

 pilis Jlavo-alhis ; abdomine lineari, maculis bis tribusjlavis, liberis ; pedihus nigris, 

 genubus luteis, tibiis tarsisque anteriorihus obscuris ; alis sub-liyalinis, stigmatefusco. 



Long. 3} — 4 lin. 



<? . Smaller than S. umbellatarum and considerably resembling Platychinis 

 scufatus S ) eyes bare, epistoma yellowish-white, yellower on the knob, and some- 

 what obscurely darkened on the sides of the mouth, there are several mostly pale hairs 

 on the sides of the disc and close to the lower part of the eyes, the upper angle of the 

 mouth is blackish ; the cheeks are clear pale yellow, with pale pubescence ; the frons 

 is yellow, with just the upper angle blackish, it is clothed with a tolerable number of 

 longish black hairs, which, however, do not spread over its middle ; the vertex is 

 rather elongate-triangular, seneous, with longish hairs, generally black, but sometimes 

 those behind are luteous ; antennse dull blackish, third joint short ovate. 



Thorax shining seneous, finely and verj^ sparingly punctate, with faint indications, 

 especially in front, of two dull dark lines down the middle of the disc, the pubescence 

 all silky whitish-yellow ; a yellow line along the sides fomis a distinct spot on the 

 shoulders, and a less distinct one on the upper corner of the hinder angles ; the breast- 

 sides have a whitish pubescence ; the scutellum is bright yellow, with a slight seneous 

 tinge, and the extreme corners seueous, it is clothed with not very abundant long 

 silky whitish-yellow hau-s ; alulse and their fringes yellowish-white ; halteres yellow, 

 obscure at the base. Abdomen linear, dull velvety-black, faintly transversely rugose ; 

 about the middle of the rather long second segment near the edge on each side is a 

 very small distinct yellow spot ; near each basal corner of the third segment, but not 

 touching the margin at all, is a larger irregidarly quadrate yellow spot ; these spots 

 are distant from each other rather less than their own breadth ; on the same part of 

 the fourth segment are similar but rather narrower spots, and the basal corners of the 

 fifth segment are entirely yellow ; the pubescence down the edge of the abdomen is 

 whitish-yellow, rather long, decreasing in length to half way down the fourth segment, 

 after which it is short and black ; on the disc, the pubescence is slight and obscure, 

 but the longer hairs seem pale, and the others rusty-black ; the belly has only the ends 

 and edges blackish, all the disc being whitish, with obscui-e markings on the sides of 

 the second and third segments ; the genitalia are very small and blackish. Legs didl 

 black, the tips of the anterior femora dull luteous, the knees brighter, the hind 

 knees very narrowly dull luteous, the anterior tibiae and tarsi brownish, with a ten- 

 dency to yellow at their tips, the hind trochanters somewhat luteous ; there is a 

 moderate whitish-yellow pubescence behind the anterior femora ; the hind metatarsus 

 is long, scarcely thickened. Wings slightly greyish, stigma distinct, brownish. 



I caught three males of this species at Rannoch in June, 1870. 

 It is, apparently, most allied to S. gutfatus, Meigen, but I am informed 

 by Loew that there are several distinctive characters ; according to 

 descriptions, ;S^.yz«^^rt^»s has a much more conspicuous, sharply-defined 

 line down the sides of the thorax, and a pair of conspicuous whitish 

 spots before tlie scutellum, and paler legs than Jlatifrom. 



{To he couii.tued). 



