THE DIPTEROUS GENUS DOLICHOPUS IN NORTH AMERICA. 25 



34. Cilia of hind femora very short, not over one-fifth as long as the uidtL of the 



femora (Louisiana; New Jersey) No. 201, dtstinctus, new variet3^ 



Cilia of hind femora at least half as long as the width of the femora 35. 



35. Second joint of fore tarsi about equal the fifth in length (Eastern States). 



No. 200, funditor Loew. 



Second joint of fore tarsi about equal in length to fourth and fifth joints taken 



together (Louisiana) No. 201, distinctus, new v^ariety. 



36. Fore tarsi with the first four joints yello'w, fifth black, compressed, but rather 



small (Eastern States) No. 212, ruficomis Loew. 



Fore tarsi with the two first joints yellon , third and fourth black, fifth white 



(New York; Minnesota) No. 199, ainshei, new species. 



Fore tarsi with the first, second and basal half of third joint yellow, the remainder 



black; third and fourth joints fringed above with long black hairs 37. 



37. Cilia of hind femora distinctly longer than the width ol the femora (widespread) . 



No. 215, cxiprinus Loew. 



Cilia of hind femora not half as long as the width of the femora (New York; 



Canada) No. 216, absonus, new species 



38. Basal half of hind coxae blackish, at least on outer surface 39. 



Hind coxae wholly yellow 46. 



39. Fore tarsi with the second joint nearly one-fourth longer than fifth 40. 



Fore tarsi with the second joint as long as the first, or shorter 41. 



40. Lamellae of the hypopygium scarcely twice as long as wide (Western States). 



No. 207, tenuipes Aldrich. 

 Lamellae four times as long as wide (California)... No. 211, superbus, new species. 



41. Fore tarsi with the first and second joints of nearly equal length 42. 



Fore tarsi with the second joint distinctly shorter than the first 43. 



42. Third joint of fore tarsi longer than the second (Western States). 



No. 206, canaliculatus Thomson. 

 Third joint much shorter than the second (Wyoming; Colorado). 



No. 152, seratus, new species. 



43. Hypopygial lamellae with a deep incision on upper edge (Western States). 



No. 209, duphcatus Aldrich. 

 Hypopygial lamellae normal 44. 



44. Empodium large, white, forming a conspicuous white tip to the tarsi (Wash- 



ington) No. 198, plumosus Aldrich. 



Empodium small, or at least not consnicuobsly large 45. 



45. Wings with a small lobe at tip of sixth vein; costa not enlarged at junction of 



first vein; middle basitarsi with a large bristle above, hind basitarsi only a 



little yello\v at base (California) No. 151, completus, ne^ species. 



Wings without such a lobe: costa with a long tapering enlargement; middle basi- 

 tarsi without a bristle above; hind basitarsi yellow with the tip narrowly black 

 (Western States) ; No. 195, occidentalis Aldrich. 



46. Tarsal ornamentation in the form of a fringe of long black hairs on upper edge of 



third and fourth joints of fore tarsi, none of the joints much compressed. . 47. 

 Fore tarsi with one or more compressed joints 48. 



47. Wings long and narrowed at base, >Aith a very small lobe at tip of sixth vein 



(widespread) No. 213, longipennis Loew. 



Wings of ordinary form, rather evenly rounded behind (Illinois; Indiana; 



Ontario) No. 214, sarotes Loew. 



48. liast three joints of fore tarsi compressed, third white, fourth and fifth black with 



white tips (Kansas; Texas) No. 202, willistonii .\ldrich. 



Third joint of fore tarsi not compressed 49. 



49. Fifth joint of fore tarsi wholly white (Louisiana). .No. 201, distinctus, new variety. 

 Fifth joint of fore tarsi partly or wholly black 50. 



