A new species of the genus Achalinus (Squamata: Xenodermidae) from Son La Province, Vietnam.

A new snake of the genus Achalinus Peters, 1869 is described based on an adult male specimen from Son La Province, Vietnam. Achalinus vanhoensis sp. nov. can be distinguished from its congeners by a combination of the following characters: 1) maxillary teeth 32; 2) suture between the internasals distinctly longer than that between the prefrontals; 3) loreal fused with prefrontal, prefrontals stretch towards the supralabials; 4) dorsal scales in 252323 rows, keeled; 5) supralabials six (left) and seven (right); 6) infralabials six; 7) temporals 2+2, the two anterior temporals in broad contact with eye; 8) ventrals 176; 9) subcaudals 84, entire; 10) cloacal entire; 11) dorsum in preservative dark purple grey above; 12) venter somewhat lighter with yellow-edged scales in the chin region, including infralabials; 13) posterior edges of ventrals and subcaudals with yellow margin. In the molecular analysis, the new species is recovered as a sister taxon of Achalinus timi, a species endemic to Vietnam, and genetically the two species are around 5% divergent from each other based on a fragment of the mitochondrial COI gene. This discovery brings the number of Achalinus species known from Vietnam to nine.

A new species of Lycodon Boie, 1826 (Serpentes: Colubridae) from Thanh Hoa Province, Vietnam.

We describe a new species of the genus Lycodon based on an adult male specimen from Thanh Hoa Province, Vietnam. Lycodon namdongensis sp. nov. is differentiated from its congeners by a combination of the following characters: dorsal scales in 17-17-15 rows, all smooth; supralabials 8; infralabials 10; one large loreal on each side, separated from the eye; cloacal single; ventral scales 218 (plus two preventral scales); subcaudals 85, paired; a total length of 723 mm; tail / total length ratio 0.205; dorsal head pattern whitish grey; dorsal surface of body with 23 narrow greyish cream bands; dorsal surface of tail with 14 cream bands; ventral surface of body mostly cream with a few small dark spots posteriorly; ventral surface of tail dark grey. Based on molecular comparisons, Lycodon namdongensis sp. nov. is recovered as a sister species to L. futsingensis with strong support values from all three analyses. The new species is at least 6.5% genetically divergent from other species within this clade as shown by a fragment of more than 1000 pbs of the mitochondrial cytochrome b. This discovery increases the number of Lycodon species known from Vietnam to 15.