TROPIDONOTUS 157 



and as high up as 7,450 feet in the Italian Alps. 

 With the exception of a few districts in England and 

 in Central Europe, as well as in the extreme north, 

 it is common everywhere, in the north as well as 

 in the south. On the Mediterranean islands it is 

 absent from the Baleares and Malta. In North 

 Africa it is known from Algeria and Tunisia, north 

 of the Atlas, where it does not seem, however, to 

 be at all common. It has a wide range in Asia, 

 extending eastwards to Lake Baikal, and southwards 

 to Cyprus, Asia Minor, and Northern Persia. In 

 the south-east of its range, the bilineated variety 

 predominates over the typical form. The melanistic 

 so-called varieties are not geographically restricted, 

 but occur all over the habitat of the species, though 

 not recorded from England. 



Habits. — Although fond of water, and often seen 

 swimming in ponds or streams or creeping by the 

 water's edge, this snake is far less aquatic than its 

 two congeners described hereafter ; it often occurs 

 on dry chalk hills or in woods far from any water. 

 It is moderately agile in its movements, and easily 

 caught, on which occasions it hisses loudly and 

 emits a nauseous smell from its anal glands, together 

 with the renal dejections, but makes no attempt to 

 bite ; exceptionally an individual may go so far as 

 to strike with open mouth, but cases of this snake 

 really biting are extremely rare. However, Gene 

 says of the male of his Natrix cettii, " iracundum et 



