THE DIPTEROUS GENUS DOLICHOPUS IN NORTH AMERICA. 17 



2. Hind femora blackened at tip, at least on upper surface 3. 



Hind femora not at all blackened at tip 14. 



3. Middle tibiae with very long slender bristles, their basitarsi vnth a row of very 

 [ long hairs ; fore tarsi compressed (eastern) No. 79, comatus Loew. 



Middle tibiae and basitarsi without unusually long bristles and hairs 4. 



4. Fore tarsi with one or more joints compressed and dilated 5. 



Fore tarsi plain ." 6. 



5. Hind femora ciliated; fore tarsi with the fifth joint only slightly dilated, their 



basitarsi scarcely as long as second and third taken together (Alaska). 



No. 81, barycnemus Coquillett. 

 Hind femora without cilia; fore tarsi with the fifth joint conspicuously dilated, 

 their basitarsi nearlyas long as the remaining four joints taken together (Massa- 

 chusetts; Maine ; New Jersey) No. 80, virga Coquillett. 



6. Fore coxae yellow, sometimes considerably blackened at base on outer surface. 7. 

 Fore coxae blackish almost to their tips ] ] . 



7. Hind femora ciliated with long hairs on lower inner edge 8. 



Hind femora without cilia 9. 



8. Hind femora with one preapical bristle, their cilia long and delicate; anal angle of 



wing nearly obsolete (New Hampshire) No. 77, obsoletus, new species. 



' Hind femora with two or three preapical bristles, their cilia stout, scarcely as 

 long as the width of the femora; anal angle of wing prominent (Massachusetts; 

 New York; New Brunswick) No. 78, trisetosus new species. 



9. Face ochraceous or grajosh yellow; hypopygial lamellae about as long as wide 



(Wisconsin; Michigan) No. 70, apfwles Melander and Brues. 



Face silvery white 10. 



10. Hypopygial lamellae triangular with a sharp point at one corner, very narrowly 



bordered with black; wings wholly grayish (Maine ; Ne^vfoundland). 



No. 75, genualis, new species. 

 Hypopygial lamellae oval, a little longer than wide, with black border; wings 

 tinged with brown in front of third vein (New York; Illinois; Ontario.) 



No. 72, discolor, new species. 



11. Wings more or less clouded with brown 12. 



Wings wholly grayish, or nearly so 13. 



12. Apical portion of wing with a conspicuous blackish spot; fore femora not darker 



on upper surface (Illinois) No. 76, praeustus Loew. 



Costal margin of wing brownish, darker in front of second vein; fore femora 

 brownish on upper edge (Washington) No. 71, affluens, new species. 



13. Bend in last section of fourth vein small but not unusually so, third vein bent 



backward at tip (Eastern States) No. 73, sincerus Melander. 



Last section of foiurth vein only slightly bent, third vein only a very little bent 

 back at tip (Eastern States) No. 74, sincerus, var. subdirectus, new variety. 



14. Front piu-ple, blue or violet 15. 



Front green or bronze colored 19 . 



15. Last joint of fore tarsi compressed and dilated (Massachusetts; New Hampshire; 



New York) No. 117, porphyrops, new species. 



Fore tarsi plain 16. 



16. Last section of fourth vein forked (widespread) No. 100, ramijer Loev/. 



Last section of fourth vein only bent, without a stump 17. 



17. Hind femora ciliate with very long pale hairs (EasternStates).No. 106, setosusltoew. 

 Hind femora ciliated with black hairs 18. 



18. Antennae wholly black (widespread). ..No. 108, renidescens Melander and Brues. 

 First two antennal joints yellow with a black line above (Eastern States). 



No. 113, marginatus Aldrich. 



