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



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 between 

 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 falla- 

 cious methods of identifying snakes, the usual one adopted with relation 

 to colour and markings is the most unreliable. Attention must be given 

 to the arrangement of the scales and shields.* We must again appeal 

 to our readers to render every assistance by procuring living speci- 

 mens without which the true colouring cannot 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 granii- 

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



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 virus alive and pario 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 (Homaloj/sidcr) and the sea snakes (ffydrophiidce) 

 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 fize and constancy to deserve a special narce is called a shield 

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

 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., Atractaspis 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 Lachesis monticola is oviparous in habit. — Vide B. N. H. S. Journal.. Vol. XV, p. 729.) 



