OSTEN SACKEN ON WESTERN DIPTERA. 229 



11 (IS). Body Anthrax-lika- frontal triangle in the male unusually 



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



12 (13). Antennae approximated at base ; third antennal 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, 



Aplicelantus Loew, Cent. 



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



17 (14). Pulvilli none Leptocliilus Loew, Cent. 



18 (11). Body mot^Anthrax-like ; 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 , Toxopliora 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 epistomain the profile form a gently inclined plane; 



the latter with long and dense, bushy 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 (26). 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 antennae, 



epistoma, mouth, etc., being completely hidden, 



Anastqechus n. gen. 



32 (25). Three submarginal cells Pantarles 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 : 



J37 (38). Third antennal joint not truncate at the tip Dpibates n. gen. 



38 (37). Third antennal joint flattened, truncate at the tip : 



139 (40). Proboscis short Paracosmits (Allocotus Lw.). 



140 (39). Proboscis very long , Phthiria Meig. 



^41 (34). Three submarginal cells : 



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



