THE CLASS REPTILIA. 9 
against which we shall have to carefully consider 
and examine; and without giving them credit for 
possessing any supernatural powers, we shall find, 
I hope, that they present a most interesting study. 
Before beginning to describe various species of our 
serpents, it will be well to have a very clear under- 
standing as to the terminology employed. We have 
already classified the species above, and also enum- 
erated them. Let us consider now for a moment their 
ordinary everyday names. 
Our venomous serpent is sometimes spoken of and 
written about as “the adder,” and as often, perhaps, 
as the “viper.” These are synonymous terms, both 
correct, and both referring to Vipera berus. But in 
some books, especially the older writings, the Latin 
name of Vipera communis is used, or again Vipera 
verus may be found. These also, then, are synonyms. 
In order to avoid any confusion we shall always use 
the term Vipera berus for the adder. It is convenient 
to restrict the use of the term “viper” to the small 
red variety of the species. This reptile is not at 
present regarded as a distinct species, though, I con- 
fess, it seems to me that it might well be so. The 
scientific name of our harmless common British snake 
is Tropidonotus natrix (the Latin natriz meaning a 
water snake). In English we hear and see this species 
spoken and written of as the ring snake or as the 
grass snake, the former term having reference to the 
peculiar marking, the latter to the habit, of the reptile. 
