DISTRIBUTION OF OPHIDIANS. 
205 
in Sicily, and probably also in Calabria. This distribu- 
tion of species would appear to be modified by the nature 
of the soil which they inhabit : the first, in general, pre- 
ferring heaths, marshy and wooded places ; the second a 
dry and arid soil ; the third, rocky regions. We have 
not observed varieties of these serpents produced either by 
locality or climate ; but it is not so with several other 
snakes of Europe, which are spread over almost the whole 
extent of that continent. We may cite, as examples, the 
Coronella Isevis and the Tropidonotus natrix, and T. 
viperinus. These species, the two former of which inhabit 
almost all northern and central Europe, and the last as 
far as the 50° N. Lat., are equally found in the south of 
Europe, where they often form, besides a great number of 
accidental, several local varieties. In Spain, for instance, 
the Tropidonotus viperinus has the back longitudinally 
rayed ; the same occurs in the Tropidonotus natrix of 
the Island of Sardinia ; and specimens of this snake killed 
in Sicily present also other slight differences ; the Coronella 
laBvis also forms ^ in Italy a local or climatal variety, and 
a variety with more clear tints, which is found in the en- 
virons of Marseilles, and which replaces our Coronella in 
the south of Europe. The Coluber ^sculapii, which in- 
habits the south of Germany, is found in Dalmatia, in 
Italy, and as far as Provence. The Coluber viridiflavus 
has been found in all the south of Europe and of Greece, 
in Hungary, in Dalmatia, in Italy, in Sicily, in Sardinia, 
and even in France and Switzerland. The Coluber hip- 
pocrepis inhabits Spain and Sardinia, while the Coluber 
leopardiniis is found in Sicily, Dalmatia, and Greece ; but 
as far as I know, neither of the two species has been seen 
in Italy. The Psammophis lacertina, common in Dalma- 
tia, in Spain, and in other countries on the shores of the 
Mediterranean, has not been found either in Italy, or in 
any of the adjacent islands. The southern countries of 
Europe produce several other species of serpents, wrhich 
^ I can confidently state that the character of the pretended Coluber 
Riccioli, drawn from the undivided nasal plate, is purely accidental ; 
as one may be convinced by examining the series of specimens of that 
Coronella preserved in our museum. 
