NEW REPTILES AND A NEW BATRACHIAN FROM SIAM 2 23 



U: lib irk.--. Four dpecimeus in all were obtained. They were 

 found beneatii fallen timber. One was brouglit to me alive, and was 

 kept for some tim^. Its habits appeared to be entirel}' subterranean, 

 and were similar to those of L. isodactijlam.* I never saw it rdoove 

 ground, though possibly it emerged during the night time. In loose 

 mould it could burrow rapidly, using its snout for the purpose, the 

 limbs being folded bach along the sides of the body. 



Vipera russelli siamensis, subsp. nov. 



A geographical race differing from the typical form in possessing 

 an additional series of small, elongated spots on eitlier side ot the body, 

 interposed between the usual tiiree longitudinal rows of large ones. 



The spots composing these two extra rows are considerably 

 smaller in size than those forming the normal dorsal and lateral chains, 

 are black in colour, with or without a lighter centre, and edged entirely, 

 or in part, with white. 



in other characters this form does not differ from the typical 

 one. 



TiJi'c. From 8am Kok. Central Siani. about GO km. N. ot 

 JJangkok. Total length, 566 mm. .Scales in 2'J rows in mid-body ; 

 ventrals 103 ; subcaudals 41. 



liemarliS. I have examined four other exam[iles of this well- 

 marked race, one from Bangkok itself, and the other three from 

 Klong Rangsit, Chiengrak Noi and Lopburi respectively, all localities 

 within the central plain of Siani. They do not differ in any important 

 respect from the type. 



Many specimens of Vtperi'. russelli from India and Burma show 

 patches of small black dots upon the sides of the body, similar in 

 position to the spots found in V. r. siamensis, but in no other respects 

 resembling them. In a sijecimen from Pyawbwe, Lower Burma (lat. 

 of N. Siam), however, there is a distinct series of marks very similar 

 to those found in siamensis, but more irregular in shape and less 

 clearly defined. Possibly this represents the northern range of this 

 subspecies. 



Russell's \'iper i.s rare in Siam. Although it is evident that 



• .loiun. Nat. Hist. Sof. Sinui, I, n. 127. 

 VOL. II, .MAY 11*17. 



