We describe a new species of Cyrtodactylus on the basis of four specimens collected from the limestone karst forest of Phu Yen District, Son La Province, Vietnam. Cyrtodactylus sonlaensis sp. nov. is distinguished from the remaining Indochinese bent-toed geckos by a combination of the following characters: maximum SVL of 83.2 mm; dorsal tubercles in 13-15 irregular rows; ventral scales in 34-42 rows; ventrolateral folds prominent without interspersed tubercles; enlarged femoral scales 15-17 on each thigh; femoral pores 14-15 on each thigh in males, absent in females; precloacal pores 8, in a continuous row in males, absent in females; postcloacal tubercles 2 or 3; lamellae under toe IV 18-21; dorsal head with dark brown markings, in oval and arched shapes; nuchal loop discontinuous; dorsum with five brown bands between limb insertions, third and fourth bands discontinuous; subcaudal scales distinctly enlarged. In phylogenetic analyses, the new species is nested in a clade consisting of C. huongsonensis and C. soni from northern Vietnam and C. cf. pulchellus from Malaysia based on maximum likelihood and Bayesian analyses. In addition, we record Cyrtodactylus otai Nguyen, Le, Pham, Ngo, Hoang, Pham & Ziegler for the first time from Son La Province based on specimens collected from Van Ho District.
The purpose of this paper is to solve an overlooked nomenclatural problem involving two taxa of Colubridae, both described as Coluber korros. The first one is Coluber korros Schlegel, 1837, now Ptyas korros, a well-known and widespread species in south-east Asia. Its senior homonym is Coluber korros Lesson, 1831, a long forgotten taxon. Furthermore, these taxa are undoubtedly non-conspecific. We tentatively identify the holotype of this latter taxon as a large specimen of Coelognathus radiatus (F. Boie, 1827) and we specify its type locality as "Region of Kolkata, West Bengal State, eastern India" (the same specification of type-locality can hence be applied to the elapid Naja kaouthia Lesson, 1831). Nevertheless, following the strict principle of priority, Coluber korros Lesson, 1831 has priority over Coluber korros Schlegel, 1837. Based on the Code, we use Article 23.9 on reversal of precedence in order to preserve the use of the well-known taxon Coluber korros Schlegel, 1837 (now Ptyas korros) against its senior primary homonym Coluber korros Lesson, 1831. Finally, we consider Coluber boncorage Lesson, 1831 to be a nomen dubium.