VIPER

(Lat. a contraction of Vivipar; from vivus, alive, and paro, / bring forth.) The common name of a genus of venomous serpents which produce living young, and have a head broader than the neck, and no pits behind the nostrils. The true vipers ( Vipera) are distinguished by the head being covered with scales, like those on the back, and by the nostrils being very large. The horned viper of North Africa and the puff adder of South Africa belong to this group. The adders (Berus) have the head covered with granular scales, with larger ones intermixed in some species, and have the nostrils of moderate size. The black adder and the common adder {Berus chersea), which are the only indigenous venomous reptiles of Great Britain, are examples of this group. [s. 1309]