PREEPACE. 
No catalogue of our species of Heteroptera has hitherto 
been published. In the three volumes published of Lethierry 
and Severin’s Catalogue of the Hemiptera are about half of 
our species, but the large family of Capside and the Crypto- 
cerata have never been catalogued. 
Dr. Uhlers ‘‘List’’ has been very useful, but it was only 
a list, included Mexican species, and is now twenty years 
behind hand. The difficulties that I met have been largely 
eased by the kindness of Mr. Otto Heidemann, and especially 
valuable has been his help in the Capside, placing in my 
hands some of his manuscript notes. 
No order of American insects has been so largely con- 
trolled by Europeans as the Heteroptera. Not only have 
they described most of our species, but these descriptions are 
often in societies little known to American entomologist, and 
almost none of them in entomological journals. Volume 
after volume of our entomological journals is issued without 
a single article on Heteroptera, and when one is found it is 
short, or only a list of names, It is hoped that this cata- 
logue will encourage entomologists to devote more time to 
this order, so that our forms will be better known to us. 
The species are arranged in 30 families; those commonly 
accepted by Hemipterists. I have not used any super- 
families or higher groups, not because I do not believe in 
them, but because there is no arrangement so far proposed 
of such exceptional merit as to win general acceptance. 
Moreover, a catalogue is not the place to exhibit philo- 
sophic classifications, but to give references to the genera 
and species. 
Altogether there are 1268 species in the catalogue; the 
family Capside leads with 348, the Lygeide with 160, the 
Pentatomide with 149, and the Coreidz with 108. 
Undoubtedly many species remain to be described, but it 
will take many years to double the number. 
What is needed especially are synoptic tables of genera 
and species to be printed in our entomological journals. 
Revisions of groups will be very valuable, but monographs 
are at present impossible. So many types are in Europe 
that before much revisional work can be done, it will be 
necessary for some one to take over a set of our species 
and compare them with the types. 
