ARACHNIDA, 127 
America in the absence of Heterophrynus and of the Thelyphonid Thelyphonellus ; but 
it is linked thereto by the extension of Hemiphrynus from Mexico to Colombia, and of 
Phrynus and Mastigoproctus from Texas at least as faras Brazil. The chief distinction 
between the Antilles and the Sonoran area is the absence of Acanthophrynus from 
those islands, and between the Antilles and South America the absence of Hetero- 
phrynus, Thelyphonellus, and Hemiphrynus from the former. But the occurrence of 
Phrynus and Mastigoproctus in both the Greater and Lesser Antilles, as well as in 
Mexico and South America, points to union between these islands and the countries 
in question. 
Order SOLIFUGZ. 
With one exception the Central American genera of this Order show the same 
general geographical features as the Pedipalpi and some of the Scorpions. 
Eremobates, the type of a special subfamily, is restricted to the Southern States of 
North America and Mexico, its distribution coinciding tolerably closely with that of 
the Scorpion Vajovis in the sense that neither extends into the West Indies or into 
South America. Ammotrecha, on the other hand, which also occurs in the Southern 
States of the Union, is found in the Antilles and in South America, its distribution 
being parallel to that of the Pedipalp genera Mastigoproctus and Phrynus and of 
the Scorpion Centruroides. The exception above referred to is Hemibdlossia, one 
species of which occurs in Guatemala and the others in South Africa. This case of 
discontinuous distribution recalls that of the Scorpion Opisthacanthus, whose nearest 
allies are tropical and South African species. 
Ammotrecha and Hemiblossia belong to a subfamily represented by numerous genera 
in Africa, South-western Asia, and the Mediterranean area of the Old World, but 
unrepresented in the Oriental Region and Eastern Asia. ‘Their occurrence in Central 
America points to an Atlantic connection between the Old and New Worlds. The only 
other facts to be borne in mind in this connection are the records of a species of Desia, 
typically an African and Mediterranean genus, in Mexico, and of a species of the 
genus Lremobates in Afghanistan. Both these records, however, require confirmation, 
Order ARANEE. 
The Central American fauna of Spiders differs, as a whole, from that of the Scorpions 
and Pedipalpi in two particulars, namely, the vast number of species, genera, and 
families it is composed of and the large number of these that are common to the Old 
and New Worlds. Hence, within the limits of a short essay, it is impossible to deal 
with all the families concerned. To illustrate some of the main features of the fauna 
and to trace as far as may be its sources, I have selected therefore for detailed treatment 
