166 Dr Hancock's Observations on 



scuta, and 69 pair of subcaudal scutella ; the back is dark grey, 

 and the hind part yellow. It grows to 7 or 8 feet in length. 



One of these serpents had 204 abdominal scuta, 68 pair of 

 subcaudal scutella, and two longitudinal cavities behind the 

 vent, probably the receptacles of the ovaries ? 



Another had 206 abdominal scuta, with 2 whole scuta, and 

 *76 pair of half scuta under the tail, which was yellow, long, and 

 tapering, one-fifth of the whole length, the snake being 5 feet 

 long. 



The tail, being constantly of a deep yellow colour, forms the 

 most distinctive character and appropriate name possible for 

 this serpent. 



I have, in several instances, observed both whole and half 

 scuta behind the vent in this serpent (as occurs in the kind with 

 206 abdominal scuta), as also in some individuals of the rattle- 

 snake. In the boas, also, we find this variation occurs not un- 

 frequently. I, therefore, consider the modern distinction of 

 " Pythons,"" so far as depends on this character, as altogether 

 nugatory, and an affectation of novelty only calculated to aug- 

 ment the confusion of an almost unintelligible jargon. This 

 character I find to be common in serpents of the most opposite 

 and contrary natures possible *. 



Being told, in 1815, by Captain Mackenzie of Demerara, that 

 he had killed a snake on the shore of the Orinoko, of the kind 

 mentioned by Mr Bunting of Poraeroon, with horns or ears, as 

 Mackenzie called them, the horns being contractile, and project- 

 ing about an inch and a half, having a long tapering yellow tail, 

 and brown body ; and having had a similar account from Mr 

 .John Brumwell, of a serpent approximating very nearly in ap- 

 pearance to the snake called Yellow Tail in Demerara, with the 



• Since my stay in London, I have examined some living Pythons, so 

 called, from Java and Ceylon, and I find them to approximate very nearly 

 to the Boa Constrictor, or Conluconaru of Guiana. The Conluconaru and 

 Camudi have each a pair of nails or claws, i. e. one on each side of the anus, 

 and so have all the other species of Boa, so far as I have had opportunities of 

 observing. It appears, Iiowever, that in the female these claws are much less 

 developed than in the male, and in some are scarcely visible without dissec- 

 tion. This appendage appears to be the most certain and constant charac- 

 teristic of the Boa kind, and we know of no poisonous serpent, I believe, 

 possessing this character. 



