274 The Ohio Journal of Science [Vol. XX, No. 7, 



KEY TO MALES. 



1. Third abdominal stemite of male deeply, roundly excavated in middle 



posteriorly, produced caudally on each side in the form of two long 

 narrow processes which are armed with very long bristles that extend 

 to or beyond apex of abdomen, the tips of the bristles forming fine 

 hairs; legs of female entirely or almost entirely yellowish, the apical 

 abdominal segment furnished with some stout curved spines. 



setiventris Stein 

 Third abdominal tergite transverse at apex, not produced at each side 

 caudally, in male; legs of female entirely or almost entirely black 2 



2. Fifth abdominal stemite with some very stout sharp spines on at least a 



part of the inner margin of each process 3 



Fifth abdominal stemite with at most some setulse on part of the inner 

 margin of each process ._ 4 



3. Spines on fifth stemite extending the entire length of the inner margins 



of the processes, longest at middle spinivejitris Coquillett 



Spines on fifth stemite confined to basal half of each process, longest 

 at base marginata Stein 



4. Hind tibia with a close series of short, erect setulose hairs on one or other 



of the ventral surfaces; inferior forceps of hypopygium very long and 



slender ■ 5 



Hind tibia with at most a partial series of short setulas on the posterior 

 or posteroventral surface or on both (cf. nidicola) _. 8 



5. Fore tibia with a very weak setula at apex on posterior surface; hind 



femur with long fine bristles on entire length of posteroventral surface; 



hind tibia with anteroventral and posteroventral setulse ■.•••■. ^ 



Fore tibia with a strong, slightly curved bristle at apex on posterior side, 

 the apex of which is usually blunt; only the posteroventral surface of 

 hind tibia with erect setulose hairs 7 



6. Parafacials much wider at base of antennae than third antennal segment, 



and about one- third the width of eye; acrostichals very closely placed. 



triseriata sp. n. 

 Parafacials about as wide as third antennal segment, and about one sixth 

 the width of eye; acrostichals widely separated fusciceps Zetterstedt 



7. Hind femur with a few bristles at extreme apex of posteroventral surface 



which are directed apicad; mid metatarsus without long setulose 



hairs on dorsal surface cilicriira Zetterstedt 



Hind femur with a series of closely placed fine bristles on more than 

 apical half, which are directed basad; mid metatarsus with some long 

 setulose hairs on dorsal surface trichodactyla Zetterstedt 



8. Mid tibia with one or more anteroventral bristles on apical half 9 



Mid tibia without any anteroventral bristles 10 



9. Fore tibia with a long blunt-tipped strong bristle at apex on posterior 



side; acrostichals in a single series, which is sometimes rather irregular. 



uniseriata Stein 

 Fore tibia with a short weak sharp setula at apex on posterior side 20 



10. Fore tibia with a long strong, curved blunt-tipped bristle at apex on 



posterior side H 



Fore tibia with a short sharp pointed setula at apex on posterior side 12 



11. Mid metatarsus with very long bristles on dorsal surface; processes of 



fifth stemite each with two or three short blunt setulae at apex on inner 



side (Fig. 3) ; arista pubescent fabricii Holmgren 



Mid metatarsus with normal hairing; processes of fifth stemite without 

 short, blunt setulae at apex on inner side angustiiarsis sp. n. 



12. Processes of fifth abdominal stemite very long, much curved, slightly 



widened at apices, their tips chitinised, glossy, almost bare outwardly, 

 furnished with short pile-like hairs inwardly; eyes separated by about 

 twice the width across posterior ocelli; hind tibia with two antero- 



dorsal bristles constrictor sp. n. 



Processes of fifth abdominal sternite not as above, much shorter, and 

 usually straight, their tips not glossy 12a 



I 



