190 DIPTERA OP NORTH AMERICA. [PART II. 



third joint smaller than in the next preceding species, in the male 

 elongated-ovate, in the female considerably shorter, in both sexes 

 with a basal arista ; the first joint is always of a yellowish color, 

 the two following paler or darker brown, sometimes rather black- 

 ish. Front black. Cilia of the inferior orbit pale. Upper side 

 of the thorax brownish-cinereous, entirely opaque ; the humeral 

 corner usually brownish-yellow ; on its upper side there are several 

 dark longitudinal lines, the more distinct of which are usually a 

 delicate middle line and two stronger lines alongside of it ; the 

 latter bear the middle rows of bristles. These lines disappear, 

 however, when looked upon from another direction, and are not 

 equally distinct and sharply defined in all specimens. Scutellum 

 on the middle of the upper side gray with a metallic-blue lustre, 

 on the margin yellow. Pleurae gray, their inferior portion more 

 yellow. The metathorax blackish-gray. Abdomen in well 

 colored specimens brownish-gray, in less matured ones more yel- 

 lowish-brown ; the whole venter always pale-yellowish. The small 

 hypopygiuin is mostly shining black and rather imbedded; the 

 outer appendages are larger than usual in the species of this genus 

 and have almost the form of small filiform lamellae ; their color is 

 a dingy yellowish-brown. Coxae and feet yellowish. Femora 

 only with the usual bristles immediately before the tip. Fore 

 tibiae without bristles. Middle and hind tibia? with a moderate 

 number of short black bristles. The first joint of the fore tarsi 

 about as long as the three following, which are of decreasing 

 length, most of the fourth and the whole fifth joint black -brown. 

 Middle tarsi from the tip of the first joint more or less dusky ; 

 their first joint about as long as the four following together, which 

 are of decreasing length. The first joint of the hind tarsi much 

 shorter than the second, the following of decreasing length. 

 Tegulae with brown margin and with pale-yellowish cilia. Wings 

 tinged with gray, in the male with a cuneiform tapering towards 

 the basis ; this is not the case in the females ; the fourth longitu- 

 dinal vein is parallel with the third and ends rather exactly into 

 the tip of the wing ; the posterior transverse vein is perpendicular 

 and lies rather upon the middle of the wing in the female, consi- 

 derably beyond it in the male. 



Hab. Virginia ; New York. (Osten-Sacken.) 



