414 ON THE GEOWTH AND STRUCTURE 
upper maxillary bones, in addition to the regular poison- 
fang, I was inclined to think, that, in consequence of the 
specimen having been somewhat mutilated, its real charac- 
ter might have been mistaken, and that it probably be- 
longed to the Trimeresures of Lacepede. On appealing, 
however, to the specimens in the Museum, I found that the 
Indian snakes called Cobras, and which agree very accu- 
rately with the descriptions given by Mr Russel of certain 
varieties of the Coluber Naja^ or Spectacle-Snake, uniformly 
possess simple teeth, growing on the upper maxillary bone ; 
and hence these serpents can no longer be arranged with 
the vipers, but ought either to form a distinct genus, or be 
classed with the pseudo Boas, or Trimeresures In a 
real Pseudo Boa-f, now in the Museum, I find three 
simple teeth in the upper maxillary bone. In a common 
variety of the Coluber Naja, there is onl}^ one fixed simple 
tooth belonging to the same bone. In the Hydrus (which 
I have not yet examined) there are several. All these spe- 
cies are East Indian, or at least belonging either to the conti- 
nent itself, or to the islands scattered over the Indian Ocean. 
It would be interesting to know, if the circumstance of 
having both kinds of teeth in the upper maxillary bone be 
confined to serpents from these countries only J. 
* The variety examined by me, and of which there exist several speci- 
mens in the Museum, is the Nella Tas Pam of Russell. I have not yet 
had an opportunity of examining a specimen of that variety whence the 
whole family derives its name. It has appeared to me that the Indian 
snakes generally have the poison-fangs much smaller than the African and 
American ; but this does not seem to have any influence over the terrible 
poison destined to pass through them. 
^ Called in Bengal " Bungarum-pamma." 
$ I have placed on the table the crania of three species of snakes, ar= 
ranged according to their teeth, viz. the cranium of a perfectly harmless 
snake having simple teeth only ; that of a Cobra or Spectacle-snake, and the 
cranium of a truly poisonous one, said to have come from the East Indies, 
but which bears the closest resemblance to the common Puff-adder of Africa. 
