46 U.S. NATIONAL MUSEUM BULLETIN 27 7 



2. Wing white, halter knob white S. niveus Becker 



Wing smoky brown, halter knob brown . . . . S. bulbapennis, new species 



3. Halter knob cream 4 



Halter knob white 5 



4. Wing with whitish cast, antenna brown S. albicinctus (Rossi) 



Wing with brownish microtrichia, antenna black-brown 



S. canarius, new species 



5. Antenna red-brown or black-brown 6 



Antenna black S. limpidipennis Loew 



6. Antenna red-brown. Abdomen with three white bands, the first broad, termi- 



nalia with two long aedeagal spines S. lucidus Becker 



Antenna black-brown, three narrow white stripes on abdomen, terminalia with 

 aedeagus short S. phaidimos, new species 



PALAEARCTIC SPECIES (FEMALES) 



1 . Wing brown or with brown patches 2 



Wing hyaline 4 



2. Wing brown, body without scale-like hairs 3 



Wing hyaline with brown patches in center of cells, body clothed with flat 



scale-like hairs S. squamosus Villeneuve 



3. Halter knob white, antenna brown S. patrizi (S6guy) 



Halter knob brown, antenna black-brown . . . S. bulbapennis, new species 



4. Halter knob white 6 



Halter knob cream or tan 5 



5. Halter knob cream, antenna black, body without noticeable hair 



S. albicinctus (Rossi) 

 Halter knob tan, antenna brown, body with short hair 



S. curtipilosus, new species 



6. Antenna red-brown or black, Ml + 2 ending after the tip of the wing . . . 7 

 Antenna black-brown. Ml +2 ending before the tip of the wing 



S. phaidimos, new species 



7. Antenna with basal segments orange or red-brown, third segment brown or 



red-brown S. lucidus Becker 



Antenna with third segment black S. limpidipennis Loew 



ETHIOPIAN SPECIES (MALES) 



1 . Wing hyaline, halter knob white, antenna black-brown or brown .... 2 

 Wing milky white, halter knob white, antenna orange-brown 



S. monodi Seguy 



2. Halter knob white, abdomen with one white band 3 



Halter with base of knob red-brown, remainder white, no white stripes on the 



abdomen S. anthrax, new species 



3. Antenna black-brown; abdomen with one white band, aedeagal parameres 



slender S. balteatus Lamb 



Antenna brown darkening distally, abdomen with one narrow white band, 

 aedeagal parameres antler-like S. inquilinus S^guy 



ETHIOPIAN SPECIES (FEMALES) 



1. Wing hyaline 2 



Wing milky or brown 8 



2. Halter knob white or cream 3 



Halter knob tan, brown or black-brown 5 



