Megophrys Kuhl and Van Hasselt are an Asian radiation of terrestrial frogs which are usually associated with montane forest (Mahony et al. 2017). The Annam horned frog (Megophrys intermedia) is reported from montane evergreen forest in Vietnam and Lao People’s Democratic Republic (Stuart 2005; Hendrix et al. 2008; Nguyen et al. 2009; Tran 2013; Orlov et al. 2015; IUCN 2017; Mahony et al. 2017). The IUCN Red List assessment for the species reports an elevational range of 782–1500 m asl (IUCN 2017) although the type locality was reported to be above 1500 m asl (Smith 1921), and Tran (2013) collected a specimen at 1515 m asl. Megophrys intermedia is assessed as Least Concern (IUCN 2017) and little is known about the reproductive behaviour and life history of the species. In Lam Dong Province (Vietnam), male M. intermedia call in March (Tran 2013); on the Langbian Plateau (Vietnam), male specimens are reported to call by day and by night from March to May and specimens called from within deep crevices between boulders in streams (Smith 1921); in Xe Kong Province (Laos), males call or guard egg clutches that are laid in water in July (Stuart 2005).

We describe a new species of the genus Subdoluseps Freitas, Datta-Roy, Karanth, Grismer & Siler from a coastal area in southern Vietnam. Subdoluseps vietnamensis sp. nov. is characterized by the following morphological characters: medium size in adults (snout-vent length up to 48.7 mm); tail length/snout-vent length ratio 1.04; toes not reaching finger when limbs adpressed; 27–30 midbody scale rows, smooth; 55–57 paravertebral scales; 55–62 ventral scale rows; 64–74 subcaudal scales; frontoparietal scale single; four supraoculars; prefrontals not in contact with one another; two loreal scales; seven supralabials; ear-opening with two lobules on the anterior border; smooth lamellae beneath finger III 9 or 10 and toe IV 12–15; six enlarged precloacal scales; and four distinct black stripes on dorsum. The new species differs genetically from its closest congeners, S. bowringii (Günther) and S. frontoparietale (Taylor), by uncorrected p-distances of 10.0% and 9.5%, respectively in ND1 sequences, and clusters into the same matriline with these two congeners on the phylogenetic trees.

We report the southernmost record of the Rhinoceros Snake, Gonyosoma boulengeri (Mocquard, 1897) from Phu Yen Province, southern Vietnam, based on a single specimen collected from forest in the Ca Range. This record extends the distribution of G. boulengeri approximately 600 km south of previous records in Vietnam (Quang Binh Province, central Vietnam). A detailed description of a hemipenis is also provided for the first time.

Introduction: Among 14 species of forest skinks (genus Sphenomorphus) in Vietnam, seven were recorded from southern part of the country. Shea’s forest skink, S. sheai, was described from Kon Tum Plateau based on a single female. Similarly, the tridigital forest skink, S. tridigitus, was also described based on a single putrid and desiccated specimen found dead on a road in Bach Ma; specimens collected recently in Laos did not fully agree with the original description. Hence, additional specimens from type localities of both poorly known species are necessary to discern their morphological variation. In addition, little is known about hemipenis and distribution of the other forest skinks in southern Vietnam. Our study seeks to (1) confirm the occurrence of all known species in the area and access their distributions, (2) provide additional morphological data on poorly known S. sheai and S. tridigitus, and (3) describe hemipenial structure of known species. Methods: We analyzed the morphology of 47 specimens of forest skink collected from southern Vietnam to identify species. Scales were observed and counted under a zoom stereo microscope and measurements were taken with a digital caliper. Results: Analyses confirmed the occurrence of seven species of Sphenomorphus in southern Vietnam, including S. annamiticus, S. buenloicus, S. indicus, S. maculatus, S. sheai, S. tridigitus, and S. yersini. New specimens of S. sheai had one enlarged anterior temporal and eight or nine lamellae under fourth toe, which differed from the original description. Additional specimens of S. tridigitus from the type locality verified that the holotype has 20 mid-body scale rows and first supralabial and nasal fused, but they differed from the holotype in having upper temporal overlapped or overlapping the lower one. Fieldwork discovered 20 new localities for all seven species. The hemipenes of four species involved those with symmetric and asymmetric lobes. Conclusion: We confirm the occurrence of seven species of Sphenomorphus in southern Vietnam with 20 additional distribution records. Hemipenial structures of known species form two groups. New specimens of S. sheai and S. tridigitus differ slightly from the holotypes.