The northern white-cheeked gibbon (Nomascus leucogenys or Hylobates leucogenys) is a Critically Endangered species of gibbon native to South East Asia. Today, the Northern white-cheeked gibbon is found only in northern Vietnam and northern Laos. They were formerly also known from southern China, in Yunnan province. They were confirmed to be extinct in China in 2013.
Adult male and female Northern white-cheeked gibbons, issued by PR of China on December 7, 2002. These gibbons are sexually dimorphic, with males and females having different colourations and the former also being slightly larger.
Northern white-cheeked gibbon in Ben En National Park, issued by Vietnam on July 1, 2006. Note the name Ogilby 1840 after William Ogilby (1805–1873), an Irish-born zoologist who was at the forefront of classification and naming of animal species in the 1830-40s and served as Secretary of the Zoological Society of London from 1839 to 1847.
Northern white-cheeked gibbon, issued by North Vietnam on March 8, 1961 in a set of four animal stamps:
Posted 07/14/2026 10:06 am
) and indeed the 300F is Macaca inuus which is called today Macaca sylvanus (Barbary macaque). 
