72 KEPT I LI A. 



Trimeresurus, Lacep. 



Large plates on the head; part of their plates double, the others 

 simple.(l) 



Oplocephalus, Cuv. 



Large plates on the head; all the sub-caudals simple.(2) 



AcANTHOPHis, Daud. — Ophrias, Merr. 



Plates on the fore-part of the cranium and head; tail terminated 

 by a hook; almost all its scales simple, the extreme sub-caudal ones 

 sometimes double.(3) 



EcHis, Merr. — Scytale, Daud. 



The head covered with small scales; all the sub-caudal plates sim- 

 ple.(4) 



Langaha, Brug. 



Head covered with plates; muzzle salient and pointed; anterior 

 half of the tail completely encircled with entire rings, and the poste- 

 rior covered above and beneath with small imbricated scales.(5) 



In addition to these two tribes of Serpents, properly so 

 styled, a third has lately been recognized, in which the organi- 

 zation and armature of the jaws are nearly the same as in the 

 non-venomous serpents, but where the first maxillary tooth, 

 larger than the others, is perforated for the transmission of the 

 poison, as in the venomous serpents with isolated fangs. 



These serpents form two genera, distinguished, like those 

 of the two neighbouring families, by the covering of the belly 

 and the under part of the tail. 



(1) The Trimer^surea petite tete, Lacep. Am. Mus. IVj Ivi, 1. 



(2) The species are new. 



(3) Jlcanthophis cerastinus, Daud., V, Ixxvii; and Merr. Beytr. II, ix, or Boa pal- 

 pebrosa, Sh. ; — Ac. Brownii, Leach, Zool. Miscell, I, iii, the most venomous reptile 

 that is found in the environs of Port Jackson. 



{4) Horatta pam., Russel, II, pi. 2, or Boahoratta, Sh., or Pseudoboa carinata, 

 Schn., or Scytale bizonata, Daud., V, Ixx; — Pseudoboa krait, Schn., or Scytale 

 krait, Daud. 



(5) The Langaha of Madagascar, Lacep. I, xxii, a Serpent only known by the 

 figure ofBrugiere. 



