IV 
Introduction 
duced, usually without serrated edges. Aedeagus always with a phallo- 
base. 
HISTORICAL RESUME 
Eleven of the thirteen recorded genera were described by Stal, Schmidt, 
Lallemand and Synave, and Melichar, and these same authors together 
with Fowler, Caldwell, Van Duzee, Doering, Metcalf and Bruner are 
responsible for most of the species recognized in this catalogue. Melichar 
1923a: 4 gives keys to and descriptions of the eleven genera that were 
known at that time and a detailed catalogue of the known species. 
GEOGRAPHIC DISTRIBUTION 
All the species in this family with the exception of nine are from the 
Western Hemisphere. Six of the nine species from the Eastern Hemi¬ 
sphere are from the Ethiopian Region. In the Western Hemisphere they 
range from Canada throughout the United States, Mexico, Central 
America, and the West Indies southward through Colombia, Ecuador, 
Peru, Brazil, and Uruguay to Argentina. The genus Philatis with six 
species is found only in the Galapagos Islands. 
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 we have 
indicated the distribution 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. 
THE PURPOSES TO BE SERVED BY A CATALOGUE OF INSECTS 
A catalogue of animals should serve practically all fields of biology. It 
should be, therefore, as complete a listing of all the records of families, 
subfamilies, tribes, genera, species, and varieties as it is possible for the 
author to assemble. The nature of the reference is of the greatest impor¬ 
tance. A student of zoogeography should be able to find a complete list of 
the regions inhabited by the various species. The student of ecology 
should be able to find references to all that is known about the life his¬ 
tory, food plants, and other pertinent data. The student of economic 
entomology should be able to check the histories of those species that 
are suspected of being injurious to plants. The plant disease specialist 
should be able to check the current nomenclature of the species which 
are disease vectors or suspected of being disease vectors. Those research 
workers studying morphology, physiology, or genetics should be able to 
