70 VIPERADiE. 



palatine bone on each side. Neck rather smaller than the 

 back of the head, from which the body increases to nearly 

 the middle of the entire length ; the rest of the body to 

 the vent scarcely diminishing; the tail becoming almost 

 abruptly smaller, and tapering to its extremity, which is 

 pointed ; the tail varies in its proportion to the body, but 

 is generally not more than one-eighth of the total length, 

 and in some even less. The head is covered with small 

 squamous plates, which in some specimens are regularly 

 formed and symmetrically placed ; but in others they are 

 very irregular. There are three which are larger than the 

 others, — namely, the vertical, and the pair of occipital 

 plates. The scales of the back and sides are semi-oval, or 

 somewhat lanceolate, imbricated, and distinctly carinated ; 

 they are disposed in eighteen series. The plates of the 

 abdomen have nothing particular in their form ; they vary 

 in number, but usually consist of about one hundred and 

 forty to one hundred and fifty, and those of the tail are 

 about thirty-five pairs. 



The general ground-colour varies considerably. In 

 some it is nearly olive, in others a rich deep brown, and in 

 others a dirty brownish yellow; and when in high health, 

 aud shortly after having cast the skin, the surface is 

 slightly iridescent in particular lights. A mark between 

 the eyes, a spot on each side the hinder part of the head, 

 and a zigzag line running the whole length of the body 

 and tail, formed by a series of confluent rhombs, as well as 

 a row of small irregular triangular spots on each side, all 

 of a much darker hue than the ground-colour of the body, 

 and frequently almost black. I have a specimen in my 

 collection which T received alive from Hornsey Wood, the 

 ground of which was almost perfectly white, and all the 

 markings jet black. The under parts are plumbeous in 



