PLATE XXI. 

 MALE GENITALIA 



1. Lateral view of Tibicen bifidus. 



2. Caudal view of Tibicen bifidus. 



3. Lateral view of Tibicen superba. 



4. Caudal view of Tibicen superba. 



5. Caudal view of Tibicen vitripennis. 



6. Lateral view of Tibicen vitripennis. 

 1. Caudal view of Tibicen eugraphica. 

 8. Lateral view of Tibicen eugraphica. 



f.360) 



