SERPENTS. 53 



sub-caudal ones hardly differ from the rest; the tail itself, however, is 

 long and pointed*. 



CoLUBEiif, Lin. 



The Snakes comprise all those Serpents, venomous or non-venomous, 

 whose sub-caudal plates are divided in two, that is, which are arranged by 

 pairs. 



Independently of the svibtraction of the venomous species, their num- 

 ber is so enormously great, that naturalists have had recourse to all sorts 

 of characters to subdivide them. ^Ve may separate, in the first place, 



Python, Daud. 



The Pythons, which have hooks near the anus, and narrow ventral 

 plates, as in the Boas, from which these serpents only diifer in the double 

 sub-caudal plates on the under part of the tail. The end of the muzzle 

 is furnished with plates, and their lips are pitted. 



Some species are as large as any Boa: such is the Ular-Sawa or 



Great Coluber of the Sunda Islands, Col. jav aniens, Sch., which has 



been found more than thirty feet in length. Seb. I, Ixii; II, xix, 1 ; 



xxviii, 1 ; xcix, 2;J;. 



The last caudal plates in some of these Pythons, and the first in others, 



are simple §. This may sometimes be an accidental difference. 



Cerberus, Cuv. 



Nearly the whole of the head, as in the Pythons, covered with small 

 scales, and no plates but what are found between and before the eyes ; but 

 the hooks at the anus are wanting. Sometimes there are simple plates at 

 the base of tlie tail|l. 



Xenopeltis, Reinwardt, 



Have large triangular and imbricated plates behind the eyes, becoming 

 confounded with the succeeding ones, which merely decrease in size^. 



Heterodon, Beauv., 

 Have the usual plates of a Coluber, but the end of the muzzle is one 



* Erpcton tentacule, Lacep. Ann. Mus. II, 1, a name given to this genus by 

 Lacep., who first described it; Merrem has substituted Rhinopiuus. 



f Coluber, the Latin generic name for Serpents. 



X This Ular-sawa, or Pytlion amethiste, Daud., Boa amethystina, Schn., of which 

 we possess one great skeleton and several skins, brought from JaA'a by M. Lesche- 

 nault, is at least closely allied to the Pedda-poda of Bengal {Python tigre, Daud.), 

 Russel, XXII, XXIli, XXIV, Col. boaforviis, Sh., Boa castanca and albicans, Sehn.; 

 and it appears to us that all the pretended species of Boa of the eastern continent 

 are in fact Pythons. Ular-sawa, in the Malay language, signifies the River- Serpent. 

 The B. irticitlata, ordlnttta, rhombeata, Schn., are all Pythons. 



§ The Bora, Russ. XXXIX {Boa orbiculata, Schn.). 



II We have seen these plates simple in one individual, and double in others of the 

 same species, a proof of the little importance of this character. To this group be- 

 long the Col. rerberii.s, Daud., Russel, pi. xxii; — Homolopsis obtusatu.t, Reinw., and 

 the neighbouring species. 



^ Xenopellis concolor, Reinw. 



