230 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XV III. 



loitli a minute notch on the free edge of the ventral corresponding to 

 the keel. 



This character of keel is only seen in two other genera, viz., 

 Dendrophis and Dendr el aphis, both of which are tree snakes also. 

 In both these genera however the vertebral row of scales is 

 enlarged, and hexagonal as in the kraits (Bungarus). It is to be noted 

 that several other snakes have what may be called false keels on 

 their ventrals, that is, the ventrals are laterally angulated. False 

 keels are rather rounded (obtuse), and have no notch at the free edoe 

 of the ventral. The outlines in section may be compared roughly to 

 those of a punt, and a dinghy (see Diagram I, fig. 1, A and B). 



It is interesting to note that these false keels are to be seen chiefly 

 in those snakes which manifest a climbing habit. For instance, in 

 the genus Lycodon, witness the species aulicus. In the genus 

 Zamenis, observe the ventrals in mucosus. In the genus Coluber are 

 notably the arboreal species prasinus, frenatus, and oxycephalic. 



In some other snakes however not conspicuous climbers the same 

 may be seen, as for instance, many of the genus Simotes. In addition 

 obtuse ventral keels are to be seen in the water snake Hipistes 

 hydrinus. In McMahon's viper (Eristocophis mcmahoni) the ventrals 

 are rather acutely keeled, but there is no enlargement of the 

 vertebral row. 



The only snake I know at all like Chrysopelea is Jerdon's pit viper 

 (Lachesis jerdonii). In this the colouration is very similar, but any 

 resemblance between these two snakes ends here. They are 

 substantially different in almost every scale character. We do not 

 give a plate of Jerdon's viper owing to its rarity, and restricted 

 Indian distribution, viz : Khasya Hills (Assam.) 



Haunts. — Very opposite opinions prevail as to its haunts. Cantor 

 says it is seldom seen in trees, but more frequently on the ground 

 in the grass. Stoliczka supports this observation, and says though he 

 caught several specimens in the grass, or between low bushes, he 

 but once saw one actually on a bush. Flower on the other hand says 

 his experiences are very different in this as in other matters from 

 those related by Cantor, and he agrees with Giinther's suggestion 

 that the reason it is not more often seen in trees is because it makes a 

 too rapid retreat. 



