THE BUTTERFLIES AND MOTHS OF AFRICA. 227 
is naturally poorer still. This would seem to indicate that 
the Northern Fauna spread originally from north to south in 
comparatively recent times. 
The so-called Mediterranean Fauna is clearly identical with 
the Steppe Fauna of Western and Central Asia, where it seems 
to have originated, and to have spread westward. At present 
it extends from North-western India and Central Asia to the 
Western Mediterranean. Of the species belonging tothe Medi- 
terranean, or Steppe Fauna, some are met with on both sides 
of the Mediterranean, like the white silver-marked Huchloe 
Belemia, the genus Thais in the Papilionide, Thestor, a 
Lyceenide genus allied to the Coppers (Chrysophanus), and 
various remarkable species of brown butterflies (Satyrine). 
Others, like the curious yellow group of Huchloe, represented 
by H#. Charlonia and allies, do not enter Europe, but extend 
along the southern shores of the Mediterranean, and the 
group which I have mentioned extends from North-western 
India even to the Canaries. Others, again, like the desert 
genus Idmais, which is allied to our genus Colias, take a 
more south-easterly direction, avoiding North Africa proper, 
but curving round from North-western India into Arabia, and 
sometimes crossing the Red Sea to the opposite African coast. 
The Indian Fauna does not greatly affect either Hurope or 
Africa. A few insects belonging to characteristically Indian 
genera (Neptis, for instance) extend to South-eastern Hurope, 
and two wide-ranging species, Danaus Chrysippus, and Hypo- 
limnas Misippus which mimics it in the female, are abundant 
both in Southern Asia and Africa. D, Chrrysippus is found 
over the whole of Africa, except Morocco and Algeria, and 
in Hurope extends to Greece, while H. Misippus does not 
extend to Hurope or to any part of the north coast of Africa, 
though we find it again, probably introduced, on the north 
coast of South America, where D. Chrysippus does not occur. 
Again, there are one or two representatives of the green- 
striped group of Danaus so common in the Hast Indies, both 
in Hast and West Africa; but, as a rule, characteristic Indian 
genera are represented in Africa by allied but distinct African 
genera, or at least by species belonging to different groups 
of a large genus, such as Charawes, when it occurs in both 
countries. 
The Fauna of Western Africa is by far the richest and 
most characteristic of that continent. Perhaps the species of 
Nymphalide may be considered the most remarkable. Many 
genera peculiar to the African continent abound in very hand- 
some species on the west coast, but are only sparingly repre- 
sented, if at all, on the eastern coast. ‘The Western Iauna, 
