OPHIDIA. 833 



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

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





Ventral s. 



Sub-caudals. 



Rows of scales. 



Sikkim 



135 



47 



24 



Bengal ? (British Museum specimen) 



1.S7 



...? 



25 



Nepal 



141 



44 



23 



Sikkimi ............. 



146 



35 



25 



Yunnan 



146 



40 



23 



Do 



148 



40 



23 



Himalayas ............ 



150 



37 



26 



Darjeeling 



151 



39 



25 . 



Yunnan 



151 



41 



23 



Do. 



156 



57 



25 



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 liead-:ihields 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 oifer any specific characters. They may either be 

 absent or be represented by one or by a pair of small 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 

 Stoliczka as T. convictus^ and which he long hesitated to separate from this species. 



VIPERID^. 



Genus Daboia, Gray. 



Daboia russellii, Shaw. 



Coluber russellii, Shaw^ Gen. ZooL, 1802, vol. iii^ p. 418. 



ri2)era daioia, Daud., Kept., 1802, vol. vi, p. 119; Wagl., Syst., 1830, p. 177. 



Vipera elegans, Daud., Rept., 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 pulchell a, Gray, Zool. Misc., 1842, p. 69. 

 Daboia mssellii, Gray, Zool. Misc., 1842, p. 69; Cat. Snakes, 1849, p. 24; Glinth., Rept. B. Ind., 



1864, p. 396; Theobald, Descr. Cat. Rept., 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. 



i5 



