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Description of a new species of the genus Trimeresurus t^^] 



Zhao Er Mi Chen Yuan Hui 



(Chengdu Institute of Biology, Academia Sinica) (Hospital of the Mangshan Bureau of Forestry, Hunan) 



In the second half of September 1989, foresters of the Chenzhou area, Hunan Province, discovered on 

 Mount Mang, Yizhang County, a snake den which contained 21 juveniles. While they were catching the 

 youngs, two adults were discovered. All snakes were caught alive and kept in captivity. Mr. Chen gave two 

 youngs to the CHENGDU INSTITUTE OF BIOLOGY for identification. It proved to be a new species of 

 laotietou, described below fi^om these two living juveniles. 



Mangshan laotietou l^^l Trimeresurus mangshanensis Zhao I-'^l, sp. nov. 

 (Figure on back cover) l^^l 



Holotype: ZS 8901, juvenile male, caught in Pingkeng District, Mt. Mang (Mangshan), Yizhang 

 County, Hunan Province, altitude 700-900 m, by CHEN Guo Hua and Tao Yun Lin. 



Paratype: ZS 8902, juvenile female, same dates, place of capture and collectors as the holotype. 



Diagnose: The new species is similar to Trimeresurus kaulbacki Smith from northern Burma, and it 

 differs fi-om this latter species by: 1) the second supralabial is small and low, and it does not make the 

 border of the loreal pit; 2) a lower number of ventrals; 3) different color of dorsal blotches. 



Description of the holotype: Head subtriangular, tip of snout narrow and rounded with a sharp 

 canthus rostralis. The rostral is subtriangular, the 2/3 inferior part slightly bent towards interior, the 

 superior part slightly bent posteriorly on its upper part. Upper head-surfaces covered with small smooth 

 scales among which the supraoculars are the largest; supraoculars separated on the middle by a row of 9 

 small scales; I pair of intemasals, the second ones in term of size, widely in contact behind the rostral and 

 not separated by a small scale; 2 relatively large scales on the canthus rostralis between the intemasals and 

 the supraoculars. Nasals squarish with their anterior and posterior margins slightly rounded and projected; 

 rostrils shaped like a mantou l''°l, located in the middle of the nasals and open posteriorly; an oval-shaped 

 nasal pore on the top of the posterior margin of the loreal pit; 1 relatively small loreal located between the 2 

 preoculars and the nasal. Presence of loreal pits, the prefoveal is relatively large and in contact forwardly 

 with the nasal; the superior and inferior margins of the loreal pit are bordered respectively by a preocular 

 and a subfoveal t'*'l. Eyes relatively small, slightly globulous; an oval, vertical pupil; 2 narrow, stretched 

 preoculars, juxtaposed and bordering the superior margin of the loreal pit; the inferior margin of the pit is 

 formed by the subfoveal; 2 very small postoculars at the superior comer of the eye, 1 lower, quite elongated 

 subocular ['•^l, which runs below the inferior margin of the eye from its lower posterior part towards the 

 lower anterior border of the eye. 7 supralabials on each side of the head, first relatively enlarged, 

 completely separated fi-om the nasal, second the smallest and in contact at its superior margin with the 

 prefoveal; third the largest, separated fi-om the eye by 1-2 minute lacrimals I'^^l; fourth supralabial 

 relatively large, in contact with third supralabial just below the eye; last three supralabials relatively low 

 and slightly elongated. Mental triangular, pointed dov\Tiwards, its anterior margin wide and straight, 

 narrowing posteriorly and with a sharp tip inserted between the first iiifi-alabials pair. I pair of relatively 

 large anterior chin shields, with, behind them, several pairs of smaller scales, separated from the first pair 

 by a deep, well-defined groove. 16 infi-alabials on the left, 15 on the right, with the first pair quite large and 



