28 



15A 21 (very rarely 19, rarely 23) dorsal scale rows at midbody; less than 195 ventrals; intemasal very 

 large; 4th supralabial nearly as large as the 3rd one; two different patterns: either dull green above, 

 with large, oval, reddish, black-edged dorsal blotches, or abnost entirely blackish, heavily speckled 

 with yellow spots T. jerdonii 



15B 25 dorsal scale rows at midbody; 200 or more ventrals; intemasals very large; 4th supralabial 

 smaller than the 3rd one; dorsal surfaces dull greyish green in life or in preservative, with blackish, 

 rhombohedral dorsal blotches separated or united to one another; smaller spots on the sides; 

 symmetrical yellow lines on the head T. kaulbacki 



16A 19 (rarely 21) scale rows at midbody; 2nd supralabial not bordering the loreal pit; endemic to 



Taiwan T. gracilis 



16B 23-27 (very rarely 21) scale rows at midbody (Ovophis monticola-group) 17 



17A Subcaudals single (or rarely only a few paired) 18 



17B Subcaudals paired (or rarely a few single) 19 



18 A More than 160 ventrals; 10 supralabials, the 3rd the largest; 2nd supralabial high, bordering the 

 anterior side of the loreal pit; 3-5 scales on the upper surface of the snout between a line connecting 

 anterior borders of the eyes and the intemasals; Xizang Province O. zayuensis 



183 Less than 140 ventrals; 8-10 supralabials, the 4th the largest; 2nd supralabial bordering the 

 anterior side of the loreal pit or not; 5-7 scales on the upper surface of the snout between a line 



connecting anterior borders of the eyes and the intemasals; Vietnam and Hainan Island 



O. tonkinensis 



19A 4th (sometimes the 5th) supralabials the largest 20 



19B 3rd supralabials the largest 22 



20A 10-12 (exceptionally 8, rarely 9) supralabials; intemasals usually in contact; less than 160 

 ventrals; total number of ventrals plus subcaudals 169 to 204 21 



20B 8-9 supralabials; intemasals separated by 2 small scales; 159 or more ventrals; total number of 

 ventrals plus subcaudals 2 1 5 to 225 ; western Yunnan O. monticola zhaokentangi 



21A 23-25 (exceptionally 21 or 27) dorsal scale rows at midbody; 132-154 ventrals, 33-48 subcaudals; 



total number of ventrals plus subcaudals 169 to 193; continental China ... O. monticola orientalis 

 21B 25-29 dorsal scale rows at midbody; 144-155 ventrals, 39-54 subcaudals; total number of ventrals 



plus subcaudals 1 88 to 204; endemic to Taiwan O. monticola makazayazaya 



22A 23-25 (rarely 21) dorsal scale rows at midbody; 135-156 ventrals, 33-62 subcaudals; 8-9 



supralabials; Himalaya eastwards up to westem Yunnan, India, Bangladesh, Myanmar 



O. monticola monticola 



22B 21-23 (very rarely 25) dorsal scale rows at midbody; 127-152 ventrals, 22-54 subcaudals; 7-9 



(exceptionally 10) supralabials; Vietnam, Thailand, Malaya, Sumatra 



O. monticola convictus 



