OSTEN SACKEN ON WESTERN DIPTERA. 229 



11(18), Body Anthrax-like; froutal triangle in the male unusually 

 large ; frontal space iu the female of a corresponding size : 



12 (13). Antennae approximated at base ; third anteunal joint gradually 



attenuated Oncodocera Macq. 



13 (12). Antennae remote at base; third joint subglobular at base, sud- 



denly contracted, and then linear, styliform : 



14 (17). Pulvilli distinct : 



15 (16). Second submarginal cell appendiculate, 



AplKxlantus Loew, Cent. 



16 (15). Second submarginal cell not aj)pendiculate, Triodites nov. gen. 



17 (11). Pulvilli none Lejytochilus Loew, Cent. 



18 (11). Body not Anthrax-Vike ; frontal triangle in the male small : 



19 (22). Body (antennae, thorax,.abdomen) clothed with more scales than 



hairs, gibbose, the abdomen hanging down ; antennae long, 

 first joint unusually long : 



20 (21). Four posterior cells Lepidophora Westw. 



21 (20). Three posterior cells Toxoj^liora Meig. 



22 (19). Body clothed with hairs, or else nearly glabrous: 



23 (44). Four posterior cells: 



24 (33). First posterior cell closed : 



25 (32). Two submarginal cells : 



26 (29). First basal cell longer than the second: 



27 (28). Front and epistoma in the profile form a gently inclined plane; 



the latter with long and dense, bnshy pile; head narrower 

 than the body Bombylius Lin. 



28 (29). Front and epistoma in the profile nearly vertical, without bushy 



pile; head large, as broad as the body; thorax large, more 

 bulky than the abdomen Comastes n. gen. 



29 (20). Both basal cells of equal length: 



30 (31). Under side of the head moderately pilose, and hence its different 



parts (including the base of the antennae, the oral edge, etc.) 

 easily perceptible Systcechus Loew, Beitr. 



31 (30). Under side of the head densely pilose, the root of the antennte, 



epistoma, mouth, etc., being completely hidden, 



Anastocchus n. gen. 



32 (25). Three submarginal cells , Pantarhes n. gen. 



33 (24). First posterior cell open : 



34 (41). Two submarginal cells: 



35 (36). Both basal cells of equal length Sparnopolius Loew, Beitr. 



36 (35). First basal cell longer than the second : 



37 (38). Third antennal joint not truncate at the tip Epihates n. gen. 



38 (37). Third antennal joint flattened, truncate at the i\\} : 



39 (40). Proboscis short Farocosmus (Allocotus Lw.). 



40 (39). Proboscis very long .Phthiria Meig. 



41 (34). Three submarginal cells : 



42 (43). Proboscis long; abdomen convex - Lordotus Loew, Cent. 



