12 Records of the Indian Museum. [Vol. XIII, 



enough to receive several species of Trimeresuri. I make out that 

 Trigonocephalus malahariciis is specifically distinct from T. anamal- 

 lensis, and I give below separate diagnoses for them. I retain the 

 specific name of the former species given by Jerdon. 



Lachesis anamallcnsis ' (Giinther). 



Trinu'i'esiinis anamallensis, Boulengcr, Faun. Brif. Ind .. Rept.. p. 4.^1 

 (in part only) ; Giinther, Repf. Bvit. hid ., p. 3S7. 



Head considerably longer than broad, in the ratio of 5 to 3, 

 and distinctly triangular. Snout far more acute than round, and 

 the temporal swellings modest. Scales on the margin of snout in 

 front more or less concave ; they may form a distinct outer ridge in 

 some cases. Scales on the head small, cycloid, slightly imbricate. 

 Those on the snout and the scales adjacent to the supraoculars 

 are slightly larger. Internasals separated by a big scale. Supra- 

 loreal descends to connect the nasal and the second upper labial 

 which forms the anterior boundary of the facial pit. One or two 

 intercalary scales between the nasal and the 2nd upper labial 

 rarely absent. Rostral broader than deep. The upper margin of 

 rostral visible from above. Supraocular faintly or distinctly divi- 

 ded into two. Seven to eleven scales between the supraoculars. 

 Two or three postoculars and a single subocular. The second 

 loreal slightly more than half the size of the first or the third. 

 Nine or ten upper labials separated from the subocular by two rows 

 of scales: the lower series consisting of bigger scales, the posterior 

 ones keeled. Twelve to thirteen lower labials and seven sub- 

 linguals. In some specimens the fourth sublingual is quite as 

 large as the first. Temporals fairly large and keeled. 



Body. Neck very much narrower than the posterior region of 

 body which is fairly rounded. Scales round the neck 23 to 26, in 

 the middle of body and the preanal region 21 to 23. All the scales 

 on the body keeled. Sometimes those on the posterior region 

 smooth, hexagonal, non-imbricate. Scales on the thickest portion 

 of the body large. Ventral shields : 147 (138 to 155, Boulenger). 



Tail perfectly rounded, acutely pointed and strongly prehen- 

 sile. In spirit specimens the tail may become twice coiled. 

 Subcaudals, two rows 47 (44 to 58, Boulenger). 



i Major Wall adopts the nomenclature of Dr. Noguchi and perhaps the 

 justification for such a procedure is that it is more convenient to have a common 

 terminology. In such a case Bothrops, Trigonocephalus, TrimeresiLriis and 

 Lachesis would be synonymous generic terms, but it is doubtful whether the gene- 

 ric identity of the Asiatic and the American species has been established. Dr. 

 Xoguchi agrees with Stejneger that the South American Lachesis is sufficiently 

 characterized by the peculiar scutellation of the tail. Apart from this, the more 

 (,v less prehensile nature and the shortness of the tail in the Asiatic forms and 

 other general characteristics peculiar to this group are sufficient for Stejneger to 

 employ the designation of Trimeresiirus for these forms. But Nogaichi considers 

 that there is greater affinity between the Asiatic and New World pit-vipers than 

 there are differences and accordingly uses the common generic name Lncliesis. It 

 has the merit of simplicity and in this paper his terminology is followed. 



