VIPERA. 235 



the sides, is a row of dirty white spots ; on the head are 

 several patches of black, a large one on the central plate, 

 which occupies the crown of the head, and afterwards 

 branches right and left, forming a V on the back of the 

 head, the branches rather curving outwards. The colouring 

 varies very greatly, a red-brown tinge sometimes pervading 

 the surface, constituting the P. chersea of Prince Buona- 

 parte's work ; the belly is dark, often blue-black. This 

 species cannot always be distinguished by its markings 

 alone from the genus Vipera, the only constant differences 

 being the narrowness of the muzzle, the plates on the 

 head, and the slighter constriction at the junction of the 

 head and spine. Individuals entirely black, except under 

 the jaws and throat, occasionally occur. 



The young are produced alive, to the number of from 

 twelve to twenty, or even more at a birth. If the Viper 

 be roused from its winter torpor and made to bite, no injury 

 ensues, the poison being at that season inert. It frequents 

 dry, sandy, and waste places. 



Entire length, about 2 feet. 



Is found all over Central Europe, as far North as Sweden, 

 in France, England, Scotland, Belgium, Germany, Switzer- 

 land, to the height of 6000 feet above the sea ; in North 

 Italy, and Siberia. In the 'Iconographia della Eauna 

 Italica,' we are informed that the variety "Chersea" 

 alone is found in South Italy, where it has occurred in the 

 Abruzzi, near the Province of Ascoli. 



Genus VIPERA. 



Head depressed, widened behind, entirely covered by 

 small scales, not by plates ; nostrils wide, lateral ; sub- 

 caudal plates in pairs throughout the whole length of the 

 tail. 



