94 THE AMERICAN NATURALIST. [Vor. XXXV. 
conditions a direct migration on land from southern Greece to 
Spain was not only possible, but was actually undertaken by 
a very large number of Oriental species." 
Chapter VII treats of the Lusitanian fauna in detail. As 
already mentioned, Dr. Scharff regards this element as the 
oldest in the British Islands, its antiquity being indicated by 
the discontinuous distribution of so many of its species. As 
Lusitanian, he regards species having their origin in the 
southwestern portions of Europe, “or on the mysterious 
lands which lay beyond it." Not all the species which have 
entered Great Britain from that direction, however, are true 
Lusitanian, inasmuch as many of the Oriental invaders are 
supposed to have traveled as far as Spain by way of the 
Mediterranean route, and then, proceeding northward, to have 
reached France, Ireland, and England. Only one mammal 
is treated of as undoubted Lusitanian, viz., Oryctolagus cuni- 
culus, the rabbit ; but several birds are mentioned as having 
a southwestern origin, prominent among which are the Dartford 
warbler (Melizophilus undulatus), the pied wagtail (Motacilla 
lugubris) and the genus Fringilla. Among the lower verte- 
brates there are more species of this kind. Thus the ances- 
tors of the amphisbzenian lizard (Blanus cinereus) are supposed 
to have entered Europe by way of the sunken * Atlantis” ; 
other probable Lusitanians are the Discoglossoid toads. and 
the salamandine genus Chioglossa. Various butterflies, beetles, 
and spiders may be similarly traced to a southwestern origin, 
but especially a large number of land mollusks, notable among 
which is the spotted slug (Geoma/acus maculosus), which is known 
only from Portugal and few localities in southwestern Ireland. 
The Alpine fauna forms the subject of the last chapter, the 
eighth. The history of this part of the fauna begins with the 
rise of the Alpine island in the Miocene sea. This island, 
being first connected with the mainland to the east, naturally 
received its first inhabitants from that direction ; and Dr. 
Scharff regards them as having formed part of the older 
Oriental invasion, many species of which, by long isolation 
and the elevation of the Alpine country, became modified into 
very distinct species, thus forming as it were a new fauna. 
