vl INTRODUCTION. 
a study of the Microlepidoptera of Tenerife published in the ‘ Proceedings of the 
Zoological Society of London’ [1907 911-1028 Pl. 51-3 (1908) ]. 
With this object the voluminous publications of Mr. Edward Meyrick on Australian 
as well as on European and Asiatic Zineina were again carefully consulted. My 
colleagues and myself have derived the utmost assistance now as in the past from his 
careful and systematic work. Indeed, whatever criticism may be brought to bear on its 
details, that work has undoubtedly supplied the guiding principles on which improve- 
ments in classification have been and may be arrived at in proportion to the amount of 
new material becoming from time to time available for further study. Mr. Busck and 
Mr. Durrant have been jointly engaged in a minute examination of a very large 
number of the types of species in my collections from all parts of the world, in making 
microscopic slides, and tabulating the numerous genera previously known, as well as 
those now first described, in a manmer which it is hoped may be found to provide a 
sufficiently workable key to their structure and development. Mr. Busck has also 
supplied further material acquired since his return to America. . 
In any case the value of co-operation in such work must necessarily be great. 
No uncertainty need exist in future as to what is the precise meaning of the terms used 
by leading authors on either side of the Atlantic; there cannot fail to be increased 
confidence between them in the knowledge that both are working on similar lines— 
their descriptions must be rendered in every way more intelligible to each other and, 
we may hope, more precise. 
There has long been a growing conviction that, for generic purposes at least, 
secondary sexual characters so mach in repute with the older writers could not be 
relied upon, and in this treatise these have been discarded in favour of distinctions 
found in both sexes. It is perhaps the first occasion on which this principle has been 
consistently applied to the classification of the Tineina as a whole. Its adoption has 
necessarily involved the suppression of a very large number of generic subdivisions, 
and of the names by which they have been distinguished. ‘his will at first be 
regarded as a very radical and perhaps presumptuous reform, especially .as here 
exemplified in the Stenomidae, Acrolophidae, Tortricidae, etc., but, when the modifi- 
cations of structure on which genera have hitherto been based in these and other 
families are carefully examined in relation to the vast number of forms in a great 
continental fauna, they are found to blend one into another by such infinitesimal 
gradations as to impede rather than to assist a conscientious worker. The genus 
Felderia, resting upon the strongly bipectinate antennae of the male, and some of 
Mr. Meyrick’s genera of Oecophoridae, founded upon differences in the length of the 
antennal ciliations, are cases in point. ‘These characters are modified by such 
