1903. ] GEOGRAPHICAL DISTRIBUTION OF SPIDERS. 359 
that region after the separation of Madagascar, and except that 
they have left isolated genera in Indo-Malaya. The Aporoptychi 
arose in Africa from the Cyrtauchenii before the severance of that 
country from South America. 
The Actinopodide were perhaps evolved from an Aporoptychus- 
like form in South America, and crossed thence to Australia. 
The Migidee probably originated in the Ethiopian Region before 
the isolation of Sokotra and Madagascar. The similarity between 
the South-African and Novo-Zelandian, the Tasmanian and Pata- 
gonian genera suggests that the migration of the family from its 
hypothetical home took an eastward direction. 
The Ctenizide, a specialised northern offshoot from the 
Cyrtauchenu, crossed during the Tertiary period from Asia to 
North America, and occur at the present time in the Senoran and 
Mediterranean Regions. It entered South-eastern Asia after the 
separation of Australia; and Africa after the formation of the 
Mozambique Channel, but before the sinking of the connecting 
land with South America. In late Tertiary times the union of 
North and South America admitted the Sonoran and Mediter- 
ranean genus Pachylomerus ito the Neotropical area, where it 
mingled with the Idiopine element that had come from Africa. 
The Halonoproctidze must similarly have crossed from America 
to Asia, or vice versa, during the Tertiary Period, since the 
existing genera persist at the present time in the Sonoran Region 
and China. 
It is impossible to determine the original home of the Bary- 
chelide. Possibly the family originated at an early date in 
Africa, and became distributed all over the area they now inhabit 
from that centre. Possibly it arose in the northern parts of 
the Old World, and at an early date extended southwards into 
the Ethiopian, Oriental, and Australian Regions. However that 
may be, there seems no reason to think that the group entered 
the Neotropical Region from the Sonoran, 
The Aviculariide arose in the northern portion of the Old 
World, whence emigrants passed into the Oriental and Ethiopian 
Regions. From one primitive type in India sprang the Thrig- 
mopeeinze ; from another in Indo-Malaysia the Ornithoctonine ; 
and from a third the Selenocosmiine, which distributed themselves 
from India, Ceylon, and the Philippine Islands into Australia, 
perhaps in Eocene times. In the Ethiopian Region, from a 
primitive type arose the Eumenophorine, at a sutticiently early 
date to reach Sokotra, 8. Arabia, and Madagasear. Later on, after 
the severance of Madagascar, arose the Harpactirine. The genera 
of these specialised subfamilies probably supplanted to a large 
extent both in the Ethiopian and Oriental Regions the Avicu- 
lariine, but the latter attained an enormous development in 
South America, which they seem to have reached from Africa or 
possibly from Europe. With the Pliocene union of North and 
South America certain forms spread northwards from South 
America into the Sonoran Region. 
