Nomascus gabriellae (Thomas 1909)
[Hylobates] gabriellae Thomas 1909, Ann. Mag. Nat. Hist., ser. 8, 4: 112.
Type Locality: Vietnam, Langbian.
Vernacular Names: Red-cheeked Gibbon.
Distribution: S Laos, S Vietnam from 15°30’N, E Cambodia.
Conservation: CITES – Appendix I; U.S. ESA – Endangered; IUCN – Vulnerable.
Discussion: Separated from leucogenys by Groves and Y. Wang (1989). Does not include siki, see Groves (2001 c).