Sept., I9I3.] Melander: Synopsis of Diptera. 253 



Head wholly or mostly black; thorax at most lightly pruinose (if the 

 frontal orbits are yellow compare superciliosa) 22. 



19. Notum and pleurae pollinose, not shining; penultimate section of the fourth 



vein much shorter than the ultimate section of the fifth vein 20. 



Thorax shining, very lightly pollinose; legs entirely black; the penultimate 

 section of the fourth vein nearly as long as the ultimate section of 

 the fifth ; four strong dorsocentrals ; calypteres and fringe yellow ; 

 bristles of the head strong. 2 mm. (Mont.*) rutiliceps n. sp. 



20. Discal cell long and narrow, the anterior crossvein beyond the end of the 



first vein ; knees sharply yellow ; four strong dorsocentrals ; five f ronto- 

 orbitals ; fringe of calypteres blackish ; wings slender, the veins 



strong. 2-2 mm. (Mont.,* Id.,* Wash.*) genualis n. sp. 



Discal cell shorter; the anterior crossvein before the end of the first vein; 

 legs entirely black 21, 



21. Dorsocentrals strong. 2 mm. (Ent. News, XXIII, 463 (1912).) (Ind.) 



davisii Walton. 



Dorsocentrals weak, hardly longer than the notal setulte ; last segment of 



5 abdomen longer than the second, third and fourth segments together, 



compressed, jet black. 2 mm. (Col.,* Id.*) auriceps n. sp. 



•22. Black, the abdomen especially greenish; two dorsocentrals; the segments 

 of the fifth vein 2--', anterior crossvein at one third the length of 

 the discal cell. (D. C, Mass., Ga., W. Ind., Wise, S. Dak.) 



viridula Coquillett. 



No trace of metallic coloring; anterior crossvein near or beyond the middle 



of the discal cell 23. 



23. Large bristly species, usually with five strong frontal bristles and with one 



or two dorsocentrals before the suture ; front very broad and uni- 

 formly opaque ; calypteres dark, with bushy black fringe ; antennae 

 brown at base; basal cells separate. (D. C, Mass.,* N. Y., Fla., 



W. Ind., La., Col., N. Mex., Cal.) setosa Loew. 



Less bristly species, not more than four dorsocentrals; antennae black; 

 calypteres white 24. 



24. Costa interrupted at the third vein or much thinned between the third and 



fourth veins; mesonotum lightly pruinose and subshining; usually a 



small dorsocentral in front of the suture 25. 



Costa continuing to the fourth vein ; as far as known, the calypteres en- 

 tirely white and fringed with white hairs ; rarely with four dorso- 

 centrals 27. 



25. Calypteres fringed with white hairs ; costa entirely interrupted at the third 



vein, (nigripes Meigen.) ' 26 



Calypteres fringed with white hairs ; costa faint beyond the third vein ; 

 discal cell moderately large; sections of the fourth vein i -.3, of the 

 fifth vein 3:2; front tibiae and all the tarsi sometimes brownish. 

 (Eur. ;* Id.,* Wash.,* Ore.*) reptans Fallen. 



26. Sections of fourth vein 1:3, of the fifth vein 3:2. (Eur.;* S. Dak.,* 



Wash.*) nigripes var. cinerascens Macquart, Strobl. 



