We describe two new insular gecko species of the genus Cnemaspis from Tarutao, Adang, and Rawi islands in Satun Province, southern Thailand. The new species are distinguished from their congeners in having a unique combination of morphological, scalation, and color pattern characters, and by genetic divergence in the mitochondrial NADH dehydrogenase subunit 2 (ND2) gene. Cnemaspistarutaoensissp. nov. was found to be a member of the C.kumpoli group, but is distinguished from all other species in that group by having 8-9 supralabials and 8 infralabials; 4-5 pore-bearing precloacal scales, pores rounded; 17-19 paravertebral tubercles randomly arranged; 27-29 subdigital lamellae under the fourth toe; subcaudal region yellowish, with smooth scales and a single enlarged median row; black gular markings in males and females; and 17.24-22.36% uncorrected pairwise sequence divergences. Cnemaspisadangrawisp. nov. was found to be a member of the C.siamensis group, but is distinguished from all other species in that group by having 10 supralabials and 9 infralabials; 6-8 pore-bearing precloacal scales, pores rounded and arranged in a chevron shape; 23-25 randomly arranged, separated paravertebral tubercle rows; 26-28 subdigital lamellae under the fourth toe; subcaudal scales keeled, without enlarged median row; gular region, abdomen, limbs and subcaudal region yellowish in males only; gular marking absent in males and females; and 8.30-26.38 % uncorrected pairwise sequence divergences. Cnemaspistarutaoensissp. nov. occurs in karst formations on Tarutao Island, while Cnemaspisadangrawisp. nov. is found near granitic, rocky streams on Adang and Rawi islands.
Keywords: Island; rock geckos; species diversity; systematics.