534 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XTJ. 



I shall not attempt to treat the subject exhaustively, as it seems to 

 me a more useful purpose will be served by dealing with the commonest 

 and most widely distributed species. Where a resemblance exists be- 

 tween two or more species, especially where one is poisonous and the 

 others harmless, they will be shown together and an attempt will be 

 made to frame easy rules whereby they may be distinguished, but here 

 I must repeat what I have said in previous papers in this Journal, viz., 

 that of all fallacious methods of identifying snakes, the usual one adopt- 

 ed with relation to colour and markings is the most unreliable. Atten- 

 tion must be given to the arrangement of the scales and shields.* We 

 mast again appeal to our readers to render every assistance by procur- 

 ing living specimens without which the true colouringwannot be shown 

 by our artists. 



The plates will show only a few inches in the middle of the body, in 

 preference to a full-length drawing which would necessarily be on too 

 small a scale in many cases to show the detail required for identification. 

 Our first plate represents the common green pit viper (Lachesis grami- 

 neus), and the common green whip snake (Dryophis mycterizans). 



Before describing our first snake I think it advisable to make a few 

 remarks on vipers in general so as to indicate their position in the snake 

 world, and the relationship of this to' other vipers. 



The word viper is derived from the Latin vivus alive undj^ario I bring 

 forth, in reference to a method of birth unusual among ophidians, but 

 not peculiar to this family. f Among our Indian representatives the true 

 fresh water snakes (Homalopsidce) and the sea snakes (Hydrophiidce) 

 also produce young. 



It is probably this viviparous habit which has led to the belief still 

 hard to dispel from credulous minds, that vipers protect their young by 

 swallowing them. A pregnant mother approaching parturition is killed, 

 and living young found within her, or observed to escape from her : the 

 erroneous conclusion is drawn that these must have been swallowed, 

 especially as it is popularly understood that snakes produce eggs. 



* Every scale of sufficient size and constancy to deserve a special name is called a shield 

 technically. The word scale is used technically to designate small and numerous forms 

 such as those on the back. 



t The rule that vipers are viviparous is not absolute. Two African species are known to 

 be oviparous, viz.,. Uractaspis irregularis and. Causus rhombeatus, and one South American 

 species, viz., Lachesis mutus. It is quite possible, too, that some Indian representatives may 

 evince a similar habit. (Since writing the above Mr. G. A. Miller has conclusively shown 

 that La;hesis monticola ia oviparous in habit — Vide B. N. H. S. Journal, Vol. XV, p. 729.) 



