Three species of the genus Amphiesma Duméril, Bibron & Duméril, 1854 have long been confused in the literature, with each other and with other species of the genus. Amphiesma khasiense (Boulenger, 1890) has been considered to inhabit a large geographical region, extending from north-eastern India, east to Vietnam and southern Thailand. Amphiesma boulengeri (Gressitt, 1937) has been regarded as a species endemic to south-eastern China. Amphiesma inas (Laidlaw, 1901) has been recorded from West Malaysia, Thailand and Indonesia (Sumatra). A multivariate analysis of morphometric and meristic characters shows that these three species can be separated by combinations of characters in the scalation and pattern, the most obvious being the structure of the postocular streak. On the basis of our analysis and after comparison with name-bearing type specimens, Amphiesma khasiense is restricted to north-eastern India, Myanmar, western Yunnan Province of China, northern Laos and northern and western Thailand. Other populations from south-eastern China, Vietnam, other parts of Laos, Cambodia and central Thailand, which have been recorded in the literature as A. khasiense, A.johannis or Amphiesma modestum (Günther, 1875), should be referred to Amphiesma boulengeri. Amphiesma inas (Laidlaw, 1901) is a valid species endemic to mountain ranges of southern Peninsular Thailand and West Malaysia. The mention of Amphiesma inas in Sumatra is erroneous, being based on the second known specimen of Amphiesma kerinciense David & Das, 2003, which is here redescribed. A key to species of the Amphiesma khasiense group and other species sharing a greyish-brown background without conspicuous dark and pale stripes, is provided.
The red-bellied form of Calliophis intestinalis (Laurenti, 1768) sensu lato was originally reported from Pahang, west Malaysia. To determine the taxonomic status of this form, we examined the type specimens of Elaps sumatranus Lidth De Jeude, 1890, Calliophis intestinalis everetti (Boulenger, 1896), and Callophis furcatus var. nigrotaeniatus Peters, 1863. The results indicated that the red-bellied form of C. intestinalis should be named as Calliophis nigrotaeniatus comb. nov., whose valid species status was based on morphological and molecular analyses. We designate a lectotype and redescribe the species, which is genetically close to Calliophis bilineatus (Peters, 1881) from the Philippines, and is clearly distinguishable from other congeners by possessing a pair of gray or dark blue lateral stripes and by being bright red on the ventrum. Elaps sumatranus and C. i. everetti are relegated to subjective junior synonyms of C. nigrotaeniatus.
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.