116 DIPTERA OF NORTH AMERICA. [PART III. 



the second; arista of medium length, with a short, but distinct 

 pubescence. The vertical diameter of the eyes more than twice 

 the length of the horizontal one. Face with very deep and long 

 antennal fovea?, which run down in a perpendicular direction ; 

 their bottom is tinged with brownish-black. The face, between 

 the fovese, is strongly, the lower part sharply carinate, and that 

 in such a manner that in profile the face runs down perpendicu- 

 larly and in a straight line. Cheeks broad ; at the lower corner 

 of the eye with an infuscated spot. Oral opening rather large, 

 somewhat drawn up above, so that the strongly' developed, 

 although transversely narrow, clypeus, projects a great deal 

 beyond the peristomium. The reddish-yellow palpi rather large, 

 broader towards the end ; the brown proboscis of medium stout- 

 ness and the reddish-yellow chin only moderately swollen. The 

 whole occiput is strongly and evenly convex. Thorax compara- 

 tively stout, but not strongly convex, distinctly narrowed ante- 

 riorly. Thoracic dorsum with a very dense, almost ochre-yellow 

 dust, and with well-defined black longitudinal stripes; lateral 

 border, and usually also the anterior one, chestnut-brownish or 

 more chestnut-red ; the intermediate stripe, running at an equal 

 breadth from the anterior to the posterior border, is divided in 

 two halves by a stripe-shaped intermediate line, which is of the 

 same breadth with both halves of the intermediate stripe itself; 

 the lateral stripes, which are but very little abbreviated anteriorly 

 and posteriorly, are crossed by the yellowish-polliuose transverse 

 suture ; their posterior part moreover has alongside of it a black 

 longitudinal stripe, which is not distinctly separated from the 

 anterior part of the lateral stripe. Pleurae chestnut-brownish, 

 about their middle with a broad longitudinal stripe, which is 

 clothed with pale ochre-yellowish pollen and gradually disappears 

 posteriorly. Scutellum brownish-yellow. Abdomen black, but 

 little shining, more or less chestnut-reddish at the extreme basis 

 and on the sides of the first two segments ; the second and each 

 of the following segments have a crossband, of a dingy ochre-yel- 

 low, very thickly laid dust, occupying almost the whole of their 

 anterior half, and narrowed on each side. The first segment of 

 the ovipositor is black, flat, broad, nevertheless strongly attenuated 

 towards its end. Feet brownish-yellow, tarsi strongly, but 

 gradually infuscated towards the end. Halteres yellowish. The 

 wings strikingly elongated, of a comparatively small and rather 



