A New Species of Rhacophorus Genus (Anura: Rhacophoridae: Rhacophorinae) from Lang Son Province, Northern Vietnam

We describe a new species of the Rhacophorus genus, which differs from its congeners on the basis of a combination of the following morphological characters: (1) medium body size (SVL of adult female — 50.4 mm); (2) head slightly wider than long (HW/HL 1.01); (3) HW/SVL 0.35; (4) HL/SVL 0.35; (5) third finger disk diameter much smaller than tympanum diameter (FTD/TD 0.70); (6) tympanum large, the lower edge of the tympanic annulus almost reaches the edge of the upper lip (TJ/TD 0.27, TJ/OJ 0.48, TJ/NJ 0.39); (7) high ratio TD/ED 0.73; (8) ratio TFL/FLL2 1.62; (9) vomerine odontophores oblique, and widely separated, between choanae (gap is equal to the length of one odontophore), touching anterior edge of choanae, vomerine teeth well developed; (10) triangular calcar absent; (11) color pattern of dorsal surface of head, body, shoulders, forearms, thighs, and shanks looks like a cross-connection between adjacent channels, tubes, fibers and other parts of a network of two general kinds of color: of reddish-brown and beige with small sparsely arranged individual black spots; (12) ventral surfaces of belly, throat, chest, femur and all forelimbs light gray, on the throat, chest and femur pigmentation is somewhat much intensive; (13) belly, throat and chest are smooth; (14) pair of tubercles ventrolaterally from the cloacal opening absent; (15) iris is brown; (16) fingers-webbing formula: I2+ – 3II12/3 – 21/2III2+ – 2IV; (17) toes-webbing formula: I11/2 – 2II1 – 2+III1+ – 21/2IV2+ – 1+V. At present, Rhacophorus trangdinhensis sp. nov. is known only by a single specimen (female) from the type locality in an evergreen forest on limestone karst from 200 m a.s.l. elevation.