COLU BRINE GROUP. 



215 



by hunger descend to the ground and rob hens' nests. That such a tiny creature 

 should be able to swallow a hen's egg seems incredible, but nevertheless a specimen 

 has been taken with the egg actually within its jaws, and the whole head so 

 swollen as to render the mouth incapable of being closed; while an example 

 in the London Zoological Gardens swallowed pigeons' eggs without any apparent 

 difficulty. When swallowed, the egg is split longitudinally by the row of teeth in 

 the throat, and the whole of the contents secured. After being thus broken, the 

 two halves of the shell, generally fitted into one another, are rejected. 



The pale snakes, or, as they are called in Brazil, the moon-snakes, 

 may be taken as our first representatives of the second of the three 

 great parallel series into which the Colubrine family is divided. This back-fanged 

 series, or Opisthoglossa, is characterised by having one or more pairs of the hinder 



Moon-Snakes. 



CROWNED MOON-SNAKE (§ liat. size). 



upper teeth longitudinally grooved, and thus capable of acting as poison-fangs. 

 Many of these snakes are indeed extremely venomous, their bite being capable of 

 producing death in a few minutes. They are divided into two subfamilies, of which 

 the first, or Dijisadince, are characterised by the lateral position of the nostrils ; 

 and they are either terrestrial or arboreal in their habits, while their distribution 

 is world-wide. 



Belonging to the first of the two subfamilies, the moon-snakes are characterised 

 by the slender and somewhat compressed form of the body; the flattened head, 

 which is but imperfectly differentiated from the neck, is broad behind and narrow 

 in front, although somewhat pointed at the muzzle; while the upper jaw projects 

 considerably over the lower. The scales, moreover, are smooth; both the anal 

 shield, and the shields on the lower surface of the tail are single ; and the eye, 

 as in most of the other members of the subfamily, has the pupil vertical. The 



