Description
English: "Faces of Lorises"
Original caption:
Fig. 1. Head of Nycticebus tardigradus malayanus = Sunda slow loris (Nycticebus coucang)
2. Head of Nycticebus tardigradus hilleri = Sunda slow loris (Nycticebus coucang)
3. Head of Loris gracilis typicus = gray slender loris (Loris lydekkerianus)
4. Head of Loris gracilis zeylanicus = red slender loris (Loris tardigradus)
Translation to modern nomenclature:
Fig. 1. Head of Nycticebus coucang coucang
2. Head of Nycticebus coucang coucang
3. Head of Loris lydekkerianus lydekkerianus
4. Head of Loris tardigradus
Note: The identity of figures 1, 2, and 4 are not certain. See review of loris synonyms
Date 1904
Source Lydekker, R. (1904) "On two lorises". Proceedings of the Zoological Society. Volume II. Plate XXIII. Available at: Biodiversity Heritage Library
Author Joseph Smit (1836–1929)
Source: https://commons.wikimedia.org/wiki/File:Smit.Faces_of_Lorises.jpg

The Sunda slow loris (Nycticebus coucang) or greater slow loris is a strepsirrhine primate and a species of slow loris native to Indonesia, western Malaysia, southern Thailand and Singapore.

The gray slender loris (Loris lydekkerianus) is a species of primate in the family Loridae. It is found in India and Sri Lanka. Its natural habitats are subtropical or tropical dry forests and subtropical or tropical moist lowland forests.

The red slender loris (Loris tardigradus) is a small, nocturnal strepsirrhine primate native to the rainforests of Sri Lanka.