bcP i': 1923 



Vol. 5, p. 65-67. August 27, 1923. 



Occasional Papers 



OF THE 



Boston Society of Natural History. 



TWO UNDESCRIBED SYRPHID FLIES FROM NEW ENGLAND. 

 BY C. HOWARD CURRAN. 



Platychirus varipes, new species. 



Allied to P. podagratus Zetterstedt of Europe, but without any- 

 long twisted hairs at the base of the front femora and with the 

 front tibiae a little more gradually dilated. 



Male. — Length, 8.5 mm. Face and front aeneous, thinly covered with 

 whitish dust, the tubercle and oral margin black. In profile the face is long 

 concave above, shortly concave below the nose-shaped tubercle; the base of 

 the antennae and the tip of the oral margin are on the same plane, the tubercle 

 occupying over one-third the length of the face and markedly prominent; pile 

 black. Front rather broad, not swollen. Sides of the vertical triangle almost 

 equilateral, the triangle bluish, with black pile except at the vertex. Occiput 

 bluish black, densely grayish poUinose along the orbits except above; the pile 

 yellow, short; the occipital ciliae long, black. Antennae black, just a trace of 

 reddish on the third joint at the base below; third joint one and one-half times 

 as long as wide, gently concave on upper surface, convex apically and ventrally. 



Thorax aeneous, with tawny-yellowish pile, some black hairs sub-laterally 

 on the posterior half. Sciitellum concolorous with the mesonotum, with 

 longer black pile but some pale hairs intermixed, especially basally. 



Legs black, the hind knees narrowly yellow; middle knees, apex of the middle 

 tibiae and the first two joints of their tarsi, reddish yellow. Front legs reddish 

 yellow, their femora with a broad brownish stripe posteriorly and a narrower 

 one anteriorly. Perhaps sometimes these stripes are more extensive and the 

 femora chiefly shining brown except the broad base and apex. Posterior half of 

 front tibiae black on the outer side for more than half their length, the base 

 yellow; front basitarsi over half white. Front femora with long, moderately 

 abundant, rather stout black hairs behind, about three of them stronger than 

 the rest. The front tibiae are gradually dilated from the base to the apical 

 fourth, thence to the apex strongly dilated, the anterior margin almost straight, 

 the outer apex produced as a small triangle. The front basitarsus is almost as 

 wide as the apex of the tibia, its posterior basal corner oblique where it receives 

 the tibial projection, one and one-fifth times as long as wide; the following 

 joints gradually and rather sharply decreasing in width and length but the last 

 joint as long as the third. Middle femora with long black pile behind and on 

 postero-ventral surface, their tibiae with conspicuous, rather abundant, fine 

 yellow pile on both the anterior and posterior surfaces. Hind femora with 

 long yellowish and blackish pile in front, their tibiae wholly black pilose. 



Wings tinged with luteous; stigma luteous. Squamae whitish with fuscous 

 border and pallid-yellowish fringe. Halteres fuscous. 



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