CHAPTER III. 



THE VIPER. 



Sub-order 3, VIPERINA ; or, OPHIDIA VIPERIFORMES. Family 

 Viperidce. Genus, Pelias. Species, berus. 



THIS being the only reptile included in these pages that I can 

 scarcely recommend as a pet, and having never harboured it 

 among my own reptilian families, there is not much to tell about 

 it. Its venomous qualities have not gained for it many ardent 

 friends and admirers ; we will therefore discuss it and dismiss it 

 for the more attractive members of the class. 



The sub-order VIPERINA is divided into the two families 

 Viperidtz and Crotalidce. It will assist the memory to observe 

 that while so many of the natural Divisions, Classes, and Orders 

 end with the letter a, the Families invariably terminate in idee. 



The Crotalidce family are not represented in England, but they 

 may be briefly described as most of them having rattles at the ter- 

 mination of the tail, as the rattlesnakes of America, and all of them 

 having a peculiar hollow or "pit " in the face on each side of the 

 nostrils, called by a French ophiologist doubles narines, but the 

 use of which is at present only conjectural. 



Some of the Crotalidcz in America have only incipient rattles 

 like this (fig. n), others have no rattles at all, but in all 

 other respects they agree with the true rattlesnakes. 



The general features of a viper are a broad, 

 angular head, distinct from the body, which is thick 

 and heavy in comparison with the colubrine snakes, 

 a short tail tapering suddenly to a point, and rough or carniated 

 scales (from carina, a keel), having a sort of mid-rib like a leaf 

 or a feather. The head, with but few exceptions, is covered with 

 scales, not plates. The English viper has a few plates, viz., one 

 over each eye, and a small pair in front, sometimes another pair, 

 or a central one; but in the matter of scales members of the 

 same family differ. At the Zoological Gardens you may some- 

 times see several English vipers in one cage, and observe the 

 variation in head-plates, though the plates are never so large ?nd 

 distinct as in the colubrine snakes. 



