Class Mammalia Linnaeus, 1758 - mammals Order Primates Linnaeus, 1758 - primates Family Cercopithecidae Gray, 1821 - Old World monkeys Subfamily Colobinae Jerdon, 1867 Genus Nasalis Geoffroy Saint-Hilaire, 1812 - proboscis monkey Nasalis concolor (Miller, 1903) - pig-tailed langur see Simias concolor Miller, 1903