Alexandre Teynié

A new genus and species of xenodermatid snake (Squamata: Caenophidia: Xenodermatidae) from northern Lao People's Democratic Republic.

A male snake collected in Louangphabang Province and a second specimen observed in Houaphan Province, North Laos, share morphological characters with the Asian genus Fimbrios Smith, 1921, including erected edges on the first supra- and infralabial scales, but differ in the following morphological characters: fewer dorsal scale rows (25-27 vs. 30-33), fewer maxillary teeth (27 vs. 30-35), posterior teeth progressively slightly enlarged, and especially the correspondence of two dorsal scale rows per ventral plate throughout the body (i.e. the first dorsal scale row made of a small scale above the fore part of a ventral, followed by a much larger scale above its hind part), a condition known only in Xenodermus Reinhardt, 1836. As the Laotian specimens differ in morphological characters from other genera and species in the family Xenodermatidae, and on the basis of molecular analyses showing a large genetic divergence from the genus Fimbrios (p-distance ≥14.7 %, mitochondrial COI gene), we place these specimens in a new genus, Parafimbrios gen. nov., and describe them as a new species, Parafimbrios lao sp. nov. Besides the characters mentioned above, the new species is diagnosed by a combination of the following ones: small, strongly keeled dorsal scales; rostral and first four supra- and infralabials with raised, erected edges; horizontal tissue ridges above the rostral; loreal single, large, elongate; ventral scales 177-189; subcaudals 55-56, undivided; dorsal colour purplish-grey, neck with a broad, very pale grey collar reaching downwards the pale grey colour of the venter. The morphological characters of the new genus are compared with those of the genera Fimbrios Smith, 1921, Xenodermus Reinhardt, 1836, Stoliczkaia Jerdon, 1870, Achalinus Peters, 1869, and Xylophis Beddome, 1878. A key to the genera Achalinus, Fimbrios and Parafimbrios gen. nov. is provided. Parafimbrios laos spec. nov. is the 111th snake species currently recorded from Laos.

A new species of the genus Opisthotropis Günther, 1872 from northern Laos (Squamata: Natricidae).

Two specimens, a male and a female, of the genus Opisthotropis Günther, 1872 were collected in a karst formation of northern Louangphabang (or Luang Prabang) Province, North Laos. These specimens are assigned to the genus Opisthotropis on the basis of their morphology, dentition and cephalic scalation. However, they differ from all other known species of Opisthotropis by a combination of the following characters: (1) 21-19 scale rows on the fore part of the body, (2) 17 scale rows at midbody, (3) 22/23 maxillary teeth, (4) 177-181 ventrals, (5) 1 loreal on each side, in contact with internasal, (6) 7 supralabials, 4th entering orbit, (7) dorsum dark bronze-brown, with upper part of dorsum darker than lateral sides, without bands or crossbars, and (8) chin and throat blackish-brown with a sharp, transversal limit with the ventral colour crossing the posterior part of the throat. As a consequence, these specimens are here referred to a new species, Opisthotropis durandi spec. nov. The new species is compared with other species of the genus, especially the most similar species O. spenceri Smith, 1918 and O. atra Günther, 1872, the type species of the genus. An updated key to the genera Opisthotropis is provided. Opisthotropis durandi spec. nov. represents the first confirmed record of a species of Opisthotropis sensu stricto from Laos and it is the 108th snake species currently recorded from the Lao Peoples Democratic Republic.