168 DIPTERA OF NORTH AMERICA. [PART II. 



B. The last segment of the fourth longitudinal vein interrupted. 



T. D. interrupting Loew. % . — Obscure virescens, modice nitens, 

 femoribus et tibiis concoloribus, genibus testaceis, tarsis fuscis, vena 

 alarum longitudinali quarta interrupta. 



Dark green, moderately shining ; femora and tibiae also green ; knees 

 brownish-yellow ; tarsi brown ; the fourth longitudinal vein interrupted. 

 — Long. corp. 0.23. Long. al. 0.20. 



Syn. Diaphorus interruptus Loew, Wien. Ent. Monatschr. V, 37, 9. — Loew, 

 Neue Beitr. VIII, 59, 6. 



Male. Rather dark green, not very shining. Face of uniform 

 breadth with the front, very broad for a male, covered with thick 

 whitish dust, so that the ground color becomes invisible, moder- 

 ately deepened and without a transverse swelling. Palpi and 

 proboscis black. Antennae black ; their first joint somewhat longer 

 than in other species; the third joint rounded; position of the 

 arista distinctly dorsal. Front with thick dusky- whitish powder, 

 so as to conceal the ground color. Cilia of the upper orbit black ; 

 the cilia of the lateral and inferior orbits are whitish and form a 

 considerable fringe. Upper side of the thorax and of the scutel- 

 lum dark-green and dull from grayish dust. Abdomen more 

 shining-green, with extensive but less thick whitish dust and on 

 the anterior part of the segments coppery to a large extent. The 

 four stout bristles on the posterior end of the small and imbedded 

 hypopygium are very prominent. Coxae black ; the fore and 

 middle coxae on the front side more black-green and fringed with 

 black bristles. Femora metallic green, stout, beset with dense 

 and coarse black hair, on the under side with numerous, but not 

 strong black bristles. Knees yellowish-brown. Tibiae on the 

 under and front side black-brown, on the upper and hind side 

 dark metallic-green, of strong structure and with unusually strong 

 bristles. Tarsi black-brown, the root of the anterior ones and 

 the under side of all the others more brownish-red ; all tarsi are 

 stouter and less elongated than in the other species known to me, 

 also with more hair ; the pulvilli are all very much enlarged and 

 elongated. Tegulae yellowish with pale-yellowish cilia. Wings 

 hyaline, scarcely a little tinged with gray, alternately with yellow 

 and brown veins ; first longitudinal vein somewhat distant from 

 the margin of the wing and reaching about as far as the middle of 

 the wing; the third longitudinal vein is very close to the second 



