INTRODUCTION 
V 
every known generic combination so that it is possible to find any species 
without recourse to the index. 
The known geographic distribution of each species is indicated by 
superscript figures at the end of the lines, which correspond to geographic 
regions designated by the same superscript figures. In general, the distri- 
bution is as given by the author of the reference, using the country as the 
smallest unit except in the larger countries where states and provinces 
are used as the smallest units. In the larger island groups the individual 
islands are indicated wherever possible in view of the importance of island 
endemism. 
An attempt has been made throughout this catalogue to interpret all 
references in the light of the period in which they were published. This is 
not always easy and leads perhaps to erroneous conclusions at times, but 
it is certainly much sounder from the standpoint of nomenclature than 
the tendency to evaluate references from previous decades in the light of 
present-day practices and procedures. 
In this series we have departed from our previous method of giving 
latinized names to varieties which in the past have been designated by 
Arabic letters, Greek letters, numbers, or other designations. All varieties 
are catalogued, however, under the first designation regardless of its form. 
Some of these varieties may prove to be valid species with further study 
and then may be given latinized designations. 
Primary homonyms of species have been replaced by nomina nova; 
secondary homonyms have been restored to their original names if the 
homonymy has been relieved by moving one or the other or both species 
to other genera. The writers take no pride in the authorship of nomina 
nova. We use them only when we think they are necessary. 
All specific endings have been modified to agree with the suggestions 
made by Blackwelder 1940, Journal of the Washington Academy of 
Sciences 31: 135-140. There are certain disadvantages inherent in this 
method, but it seems that these limitations are outweighed by the ad- 
vantages of this system. We are confronted by so many coined words 
that can have no sex that it seems better to use this system and disre- 
gard apparent violations of Latin and Greek grammar. Where the sex of 
generic names can be determined the appropriate adjustments are made 
in the specific names. 
In a detailed catalogue such as this it is practically impossible to 
eliminate all errors. We will appreciate it very much if our attention is 
directed to all such mistakes. It is especially easy to overlook local lists 
when published in the proceedings of local natural history societies, refer- 
ences to species of economic importance when published in scientific 
agricultural journals, references to vectors of plant diseases when pub- 
