INTRODUCTION. 
Tue Central-American Araneidea, to judge from the collections made by the Editors 
of this work, do not present any very remarkable forms peculiar to the region, save, of 
course, so far as particular species are concerned. ‘The collections before me include 
representatives of thirty-four families, the total number of genera being 280, and 
species 1111. It is probable that, after all, little more than the fringe of the fauna 
has been dealt with. Hundreds more, both genera and species, doubtless remain for 
the future collector to discover. 
It will be interesting to discuss briefly the spider-fauna of the district in connection 
with the local distribution of the families, and also in its relation to the fauna of other 
continental regions. We at once find that whilst the vast majority of the species 
represented are peculiar to the Nearctic and Neotropical Regions, the genera are in 
many cases identical with those indigenous to such widely distant regions as the 
Mediterranean, Palearctic, Oriental, Australasian, and Ethiopian. 
We may dismiss at once the supposition that identical or even closely allied 
genera sprang into being sporadically in various regions permanently separated by 
physical barriers such as are furnished by thousands of miles of tempestuous ocean. 
Remarkable convergencies of character may occur here and there in organisms which 
have originated from entirely distinct primitive forms, but where such resemblances 
are very abundant we are driven to the conclusion that all these forms had common 
origins respectively, and that the fauna of the various regions presenting these 
likenesses must have passed freely from one to the other, at a date subsequent, at any 
rate, to the specialization of the various genera of which representatives are found in 
each. 
In all probability only a very small number of species have been accidentally 
