11. LACHESIS. 551 



20. Lachesis cantoris. 



Ti-i^onocephalua canton, Blyth, Journ. As. Soc. Beng. xv. 1846, 



p. 377. 

 Trimeresurus viridis, var. cantori, Blyth, Journ. As. Soc. Beng. xxix. 



1860, p. 110. 

 labialis, Steindaclin. Novara, Mepf. p. 86, pi. iii. figs. 1 & 2 



(1867); Theob. Cat. JRept. Brit. Ind. p. 221 (1876). 

 cantoris, Stoliczka, Journ. As. Soc. Bmg. xxxix. 1870, p. 222, 



pi. xii. figs. 3 & 4 ; Theob. I. c. p. 222 ; Bouleng. Faun. Ind., Bept. 



p. 428(1890). 



Eostral as deep as broad ; nasal divided ; upper head-scales very 

 small, smooth, almost granular ; supraocular shields distinct-, narrow, 

 sometimes divided into two ; usually one or two scales between the 

 internasals, 16 on a line between the supraoculars ; two small post- 

 oeulars and a subocular, which is separated from the labials by two 

 or three rows of scales ; 13 upper labials, first confluent with nasal, 

 second forming the anterior border of the loreal pit ; third largest ; 

 temporals small, feebly keeled. Scales rather feebly keeled, in 27 

 to 31 rows. Ventrals 174^184; anal entire; subcaudals 55-76 

 pairs. Pale brown or dull green above, with small dark spots ; a 

 whitish streak along the outer series of scales ; whitish or greenish 

 beneath, uniform or with the base of the ventrals dark ashy or 

 blackish. 



Total length 1020 millim. ; tail 140. 



Andaman and Nicobar Islands. 



«. 2 (Sc. 31 ; V. 178 ; C. 61). Nicobars. 



'21. Lachesis jerdonii. 



Trimeresurus jerdonii, Oiinth. Proc. Zool. Soc. 1875, p. 233, pi. xxxiv.; 



Bouleng. Faun. Ind., JRept p. 427 (1890). 

 xanthomelas, Oiinth. Ann. ^ Mag. N. S. (6) iv. 1889, p. 221, 



and in Pratt, Snows of Tibet, p. 241, pi. i. fig. A (1892). 



Eostral as deep as broad or a little deeper than broad ; nasal 

 divided ; upper-head scales very small, smooth, juxtaposed ; supra- 

 oculars large, larger than the eye ; one or more scales between the 

 internasals, 7 to 9 on a line between the supraoculars ; one or two 

 small postoculars and a subocular, which is in contact with the 

 third labial, and usually separated from the fourth by a series of 

 small scales ; 7 or 8 upper labials, second forming the anterior 

 border of the loreal pit, third and fourth large ; a series of large, 

 smooth temporals above the labials. Scales strongly keeled, in 21 

 or 23 rows. Ventrals 164-188; anal entire; subcaudals 54-67 

 pairs. Greenish yellow or olive above, mixed with black ; a dorsal 

 series of transverse rhomboidal reddish-brown spots edged with 

 black ; head black above, with symmetrical yellow markings ; upper 

 lip yellow, with one or more black spots, that on the second labial 



