FIGURE 4. Head of Stegonotus caligocephalus sp. nov. (holotype, FMNH 251054) in both photographs (left column) and line drawings (right column). Shown are dorsal (A, A'), right lateral (B, B'), and ventral (C, C') views. Scale abbreviations for scales in dorsal view include rostral (R), internasals (IN), prefrontals (PF), frontal (F), supraoculars (SO), preoculars (PR), postoculars (PO), anterior temporals (AT), posterior temporals (PT), and parietals (P). In lateral view additional abbreviations include nasals (N), loreal (L), supralabials (SL, numbered), mental (M), and infralabials (IL, numbered). In ventral view anterior genials (AG) and posterior genials (PG) are labeled, as are gulars (Roman numerals). ; 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 60, DOI:10.11646/zootaxa.4894.1.2, http://zenodo.org/record/4315464