Head elongato-pyramidal, body sub cylindrical, tail very long. Nostril in a single nasal shield immediately above the labials. Dorsal scales large, strongly keeled, the keels being confluent into longitudinal ridges; all the ventral shields, or at least the lateral ones, keeled. Sides covered with granular scales. Anal shield surrounded by smaller ones; one or two inguinal pores on each side. Femoral pores none. Tail with rings of keeled, quadrilateral shields. An indistinct collar. Toes not serrated or keeled. Tympanum distinct.

Synopsis of the Species.
* All the ventral shields are keeled; three pairs of chin-shields.
1. Dorsal scales in four, ventral shields in tent longitudinal series; ventral shields in twenty­two or twenty-three transverse rows. Generally two inguinal pores on each side of the vent: Tachydromus sexlineatus, Daud., from Rangoon, Borneo, and probably from other islands of the East Indian Archipelago.
2. Dorsal scales in four, ventral shields in twelve longitudinal series; one inguinal pore on each side of the vent: Tachydromus meridionelis, n. sp., from Southern China.

3. Dorsal scales in six series: Tachydromus septentrionalis, n. sp., from Ningpo.
** Only the lateral ventral shields are keeled; four pairs of chin-shields.
4. Dorsal scales in six, ventral shields in eight series; inguinal pores two on each side:
Tachydromus japonicus, Dum. & Bibr., from Japan.
t " Six series longitudinales" (Dum. & Bibr. v. p. 160) is probably a misprint.