PER

(Lat. a contraction of Vivipar; from vivos which alive, and paro, J bring forth.) The common name of a ge- Suppose nus of venomous serpents which produce living young, and about have a head broader than the neck, and no pits behind the the nostrils. The true vipers {Vipera) are distinguished by the head being covered with scales, like those on the back, and above,be by the nostrils being very large. The horned vi|>er of North Africa and the puff adder of South Africa belong to this of F group. The adders (Berus) have the head covered with granp' ular scales, with larger ones intermixed in some species, and P' have the nostrils of moderate size. The black adder and point the common adder {Berus ckersca), which are the only in- P' digenous venomous reptiles of Great Britian, are examples of this group. Cities vi [s. 1322]