OPHIDIA. 



833 



in both entire. To illustrate the variations which occur in the ventrals and 

 suh-caudals of this species I give the following table. 



In one of these Yunnan specimens with the divided second labial, many of the 

 sub-caudals are simple. 



There is thus in. this species a variation in the ventral and sub-caudal shields of 

 21 to 32 respectively, and the preceding table would seem to indicate that when 

 there is a diminution in the number of the ventrals, there is not of necessity any 

 corresponding reduction of the sub-caudals, and vice versa. I have recorded else- 

 where,' that variations in the number of head-shields are inaugurated in utero, 

 and I have observed that the number of the ventrals and sub-caudals vary in the 

 individuals of a brood. 



The shields or scales between the supranasals, as is in other species of Trimere- 

 suri, are variable and do not offer any specific characters. They may either be 

 absent or be represented by one or by a pair of smaU scales or shields. 



An adult female measures 30 inches, of which the tail is 4-50 inches, and a 

 male 6'12 inches and its tail 3'35 inches. 



A closely allied, if separable form, is the young snake from Penang described by 

 StoKczka as T. convictm^ and which he long hesitated to separate from this species. 



VIPERID^. 



Genus Daboia, Gray. 



Daboia russbllii, Shaw. 



Coluber russellii, Shaw, Gen. Zool., 1802, vol. iii, p. 418. 



Vipera daboia, Daud., Eept., 1802, vol. vi, p. 119; Wagl., Syst., 1830, p. 177. 



Vipera elegans, Daud., Kept., vol. vi, p. 124, pi. Ixxiii ; Wagl, Syst., 1830, p. 177; Schleg., 



Phys. Serp., 1837, vol. ii, p. 588, pi. xxi, figs. 4 and 5. 

 Coluber triseriatus, Hermann, Obs. Zool., 1804, vol. i, p. 278. 



Echidna elegans, Merr. Tentam., 1820, p. 153 ; Dum. & Bibr., 1854, vol. vii, p. 1435. 

 Daboia pulcJiella, Gray, Zool. Misc., 1842, p. 69. 

 Laboia russellii, Gray, Zool. Misc., 1842, p. 69; Cat. Snakes, 1849, p. 24; Giinth., Kept. B. Ind., 



1864, p. 396; Theobald, Descr. Cat. Kept., Brit. Ind., 1876, p. 217; Stol., Journ. As. Soc, 



1 Proc. Zool. Soc, 1871, p. 180, p. 195. 



- Journ. As. Soc, Bengal, 1870, vol. xxxix, p. 224. 



1 5 



