FIGURE 1. Map of Borneo and surrounding archipelagos, including portions of The Philippines, Sulawesi, and the Moluccas. The dotted lines demarcate Wallace's Line, with larger dots representing the line according to Wallace (1860) and the smaller dots the one modified by Huxley (1868). Marked distributions of Stegonotus include the only known locality of S. borneensis in Sarawak (A; yellow dot); the holotype and paratype localities of S. caligocephalus sp. nov. (B and C, respectively; red dots); the distribution of S. muelleri in blue (Kaiser et al. 2018a), including the Philippine islands of Samar (1), Leyte (2), Dinagat (3), and Mindanao (4); islands with known records for S. batjanensis in gold (Lang 2013), including the northern Moluccan islands of Morotai (5), Halmahera (6), Ternate (7), Tidore (8), Kasiruta (9), Bacan (10), and Obi (11); and islands with confirmed records for S. modestus in green (Kaiser et al. 2018a), including Buru (12), Ambon (13), and Seram (14). The inset globe shows the position of the depicted area between Southeast Asia and Australia. Scale = 500 km. ; Published as part of Kaiser, Christine M., Lapin, Jack, O'Shea, Mark & Kaiser, Hinrich, 2020, Carefully examining Bornean Stegonotus (Serpentes, Colubridae): the montane groundsnake population in Sabah is a new and distinct species, pp. 53-68 in Zootaxa 4894 (1) on page 54, DOI:10.11646/zootaxa.4894.1.2, http://zenodo.org/record/4315464