Mammals Collected by Dr. W. L. Abbott on the Natuna Islands / Proceedings of the Washington Academy of Sciences, Vol. III, pp. 111-138
Gerrit S. Miller
MACACUS 'CYNOMOLGUS' Auct.
SEMNOPITHECUS NATUNÆ Thomas and Hartert.
SEMNOPITHECUS CRISTATUS (Raffles).
Two monkeys from Sirhassen appear to be referable to this species.