LAOHESIS. 215 



Si/no^Jsis of the Species. 



1. Scales between the eyes smooth or 

 obtusely keeled ; gulav scales smooth. 



A. Snout not prominent, not raised 



above the nostrils. 

 Supraocular shields lai'ge, separated on 



the vertex by 5 to 8 series of scales ; 



scales smooth or feebly keeled, in 21 



to 25 (rarely 27) rows ; ventruls 132- 



158 ; tail not prehensile L. monticola, p. 215. 



Siipraoculars very narrow if distinct, 



separated by 12 to 15 series of scales ; 



scales strongly keeled, in 25 or 27 



rows; ventrals 160-182; tail slightly 



prehensile L. imrpureomaculatus, p. 216. 



Supraoculars narrow if distinct, sepa- 

 rated by 8 to 13 series of scales ; 



scales nearly smooth or more or less 



distinctly keeled, in 10 to 23 rows ; 



ventrals 150-175 ; tail prehensile. ... L. gramineus, p. 217. 

 Supraoculars large, separated by 4 to 9 



series of scales ; scales feebly keeled, 



in 21 rows ; ventrals 180-191 ; tail 



prehensile L. sumatranus, p. 217. 



B. Snout ver}' prominent, the upper 



edge strongly raised above the 

 nostrils ; scales in 19 or 21 rows ; 

 ventrals 152-168 ; tail prehen- 

 sile L. horneensis, p. 218. 



II. Scales between the eyes strongly 

 keeled; gular scales obtusely keeled ; 

 scales in 21 to 25 (rarely 19 or 27) 

 rows; ventrals 127-154; tail pre- 

 hensile L. wagleri, p. 218. 



233. Lachesis monticola. 



Trimercsurus inonficola, Giinth. Rept. Brit. Ind. p. 388, pi. xxiv, 

 fig. B (1864) ; Favrer, Thanatoph. Ind. pi. xv (1874) ; Bouleng. 

 Fauu. Brit. Ind., Kept. p. 426 (1890). 



TriniereffiiruscoHvictus, Stoliczka, Journ. Asiat. Soc. Bengal, xxxix, 

 p. 224, pi. xii, fig. 1 (1870). 



Lachesis monticola, Bouleng. Cat. Sn. iii, p. 548 (1896). 



Malay name, Ular Icapar. 



Snout very short ; eye very small. Kostral as deep as broad or 

 a little broader than deep ; upper head-scales small, subimbricate, 

 smooth ; supraocular large ; 5 to 8 scales iu a transverse line 

 between tlie supraoculars ; 3 or 4 rows of scales between the eye 

 and the labials : 8 or 9 upper labials, second usually forming the 

 anterior border of the loreal pit. Scales feebly keeled or nearly 



