INTRODUCTION. xi 
' It was not originally my intention to transfer my collections and library to the 
National Museum until this work should have been completed; but the delay that 
has occurred in the elaboration of references to previous literature, and in the repro- 
duction of Mr. Frohawk’s excellent figures by lithography at Leiden, combined with 
other circumstances, rendered it impossible to postpone their departure, and the 
transference has not accelerated publication. ‘The importance of securing the majority 
of the types, as such, for our National Museum has not been overlooked, and I should 
have been better satisfied if this object could have been achieved at an earlier date. 
The publication of the monograph of the Hawaiian “ Micros,” which was in hand 
when I first began to prepare a paper for the ‘ Biologia,’ somewhat interfered with its 
earlier stages, but the great delay which has occurred in bringing this treatise to 
a successful conclusion has been for the most part due to the earnest desire of 
Mr. Durrant to carry it beyond its original scope and purpose, and to give it special 
value for the future guidance of all students of the Microlepidoptera. With this aim 
in view, he has undertaken far-reaching researches in the literature of the subject. 
He has looked up as far as possible every reference, not only to the species under 
consideration, but to the genera in which they have been placed by various authors, 
tracing the history of each genus, and, where amalgamation has become necessary, the 
type of each generic name is stated in chronological order, establishing priority which 
may be confidently accepted as such, unless an error can be subsequently proved. 
It is perhaps too much to hope that no such errors may henceforth be found, but 
there has been at least no attempt to suppress information, and the references given 
throughout should be clearly sufficient to indicate the lines on which further research 
may safely proceed. During the time that the Collections remained in my possession, 
when I was able to direct and examine the progress of the necessary comparisons and 
tabulation of genera and species, it was apparent that this work could not be done 
without much sacrifice of time and labour devoted to literary research, and the delay 
involved was even then a source of considerable annoyance and disappointment, not 
only to the Author and Projector of the ‘ Biologia’ but to myself. I had written 
a large proportion of the descriptions of new species so long ago as 1895, soon after 
Dr. Godman’s material was placed in my hands, and at that time I had every hope 
that a paper on the same lines as others in his great publication might have been 
completed within a few years at least. From that time onward not only has much 
additional material been added to the Collection, but much has been published from 
time to time affecting the questions of classification and nomenclature, as well as 
adding many species to the numbers recorded from the region included in the scope 
of the investigation. 
Since April 1910, when my Collections (including the Godman and Salvin material) 
and Library were presented to the National Museum, | have been unable to exercise 
