PREFACE. 
The following rules have been prepared for the purpose of aiding 
entomologists in deciding questions of nomenclature arising in their 
work. In preparing them the various codes of nomenclature have 
been freely consulted and used, articles on nomenclature in various 
journals read, and pamphlets on the subject have furnished some 
points. After a mass of matter was prepared, copies were sent to 
many of the principal systematic entomologists of America, in fact 
all whom we knew to be interested in such matters. Nearly all have 
expressed opinions on the more important rules, and many on almost 
every one. Various other workers have been consulted personally 
and the published utterances and catalogs of several entomologists 
have furnished opinions. After being worked over and over again 
the rules have gradually taken shape, often far from their original 
form. They have been subjected to some use in catalog making, 
type fixation, &c., and so far as possible they are brought into accord 
with the general practice of entomologists. The result, while hardly 
satisfactory to any one entomologist, expresses the opinion of sys- 
tematic workers far more accurately than the vote of any committee. 
These rules do not represent the personal desires of their prepara- 
tors, since there are several important rules which have been accepted 
reluctantly by one or both of the compilers in order to join the ma- 
jority of American systematic entomologists. As they stand there 
will probably be at least one objector to every rule, but we hope no 
one will object to all of them. The point of the use of a misidenti- 
fication as a genotype, and that on a name in synonymy preoccupy- 
ing the use of such name in the genus, provoked the most discussion, 
but the weight of opinion and of practice seems to sanction the rules 
as herein set forth. A few object to a valid specific name being re- 
quired as the basis of a genus, but by far the greater number express 
themselves as in favor of the rule. 
Rarely will two people express the same thought in the same lan- 
guage, and likewise two persons reading the same statement may 
disagree as to its meaning. An effort had been made to express the 
following rules in language as plain and definite as possible, and 
wherever it was thought helpful, examples are inserted. If the rules 
are carefully considered, in conjunction with the examples, where 
