This
species--_Blanus cinereus_--is of the size and shape of an ordinary
earth-worm, from which, however, it may be distinguished by its
snake-like wriggling motions. It lives under stones in Spain and
Portugal, North-west Africa, and Greece. It has, therefore, a somewhat
similar distribution to that of many of the animals and plants referred
to in the last chapter. But here we have an animal which has evidently
utilised the old Mediterranean route described on p. 271, from west to
east. Two other species of _Blanus_ inhabit Asia Minor and Syria, but
most of its nearest relations either live in South America or tropical
Africa. In migrating to North and West Africa, its ancestors probably
made use of the land-bridge which spanned the Atlantic in early
Tertiary times. Another Lusitanian Lizard--belonging not to an aberrant
group, but to the typical Lacertidae--is _Psammodromus hispanicus_. It is
rather variable in colour--generally of a brown or green--and grows to a
length at about four or five inches. It occurs throughout the Spanish
peninsula and also in Southern France. One of the handsomest European
Lizards, which reaches almost a foot in length,--of an olive colour with
greenish or mother-of-pearl reflection, and with two yellow stripes
along each side of the body,--is an allied species (_P. algirus_). From
the Spanish peninsula it passes into Southern France and North Africa.
Two other species of the genus are confined to North-west Africa.

It is quite possible that the genus _Pelobates_ is of south-western
origin. Of the two known species of this genus of Toads, one is found in
the Central European plain and the other on the Spanish peninsula and in
France. The closely allied _Pelodytes punctatus_, too, is confined to
this south-western district, and their nearest relations are found in
Mexico. Similarly, the genus to which the Midwife Toad (_Alytes
obstetricans_) belongs may have its original home in that part of
Europe. Of the two species, one is confined to France, Switzerland,
Belgium, and Western Germany, and the other, viz., _Alytes cisternasii_,
to Spain. _Discoglossus pictus_--a well-known and conspicuous Toad in
Southern Europe--inhabits Spain, Algiers, and Tunis, the islands of
Malta, Sicily, Sardinia, and Corsica. From the general range of the
family _Discoglossidae_, as given in Mr. Boulenger's excellent catalogue,
it appears that nowhere in the vast space between China and New Zealand
has any membe