Key to Exsul species
1 Dorsocentrals 3+4; males with wings broad and dark brown; abdomen elliptic............................ E. singularis
- Dorsocentrals and male wings and abdomen shape different from above.......................................... 2
2 Dorsocentrals 2+4; male: katepisternals 1+2 and notopleurals 2........................................... E. tenuis
- Dorsocentrals 4+4; male katepisternals 2+3 and notopleurals 4.................................... E. alfredoi sp. n.