The present booklet had its origin very many years ago in the author's idea of writing an account of the house-fly and its kindred, which would be interesting and more truthful than much then to be found in current literature. Such off-hand inconsiderate writing, as appears in the "Elements of Entomology," by W. S. Dallas, F.L.S., requires to be controverted; therein it is stated that the house-fly, which is "troublesome, does very little actual damage, for our only real grounds of complaint are to be summed up in the tickling sensation which its feet cause," &c. "In its larvæ state, however, it lives inoffensively enough in dung." It has now seemed timely to publish my long-delayed work, re-written with the object of more urgently interesting the general public in the cause of the anti-fly campaign. Still, the author trusts that both the deeper and the less entomologically inclined nature students will find therein not only useful, but also some novel information, given with not too much entomological technicality.

There is no English work sufficiently modern and comprehensive for a study of our native flies. In 1776, Moses Harris, who originated or elaborated the study of wing patterns, published his "Exposition of English Insects," in which more than 300 flies are figured and described; they have the old Linnæan classification and nomenclature, of course, and the work is scarce. All later attempts by English authors in the way of a more comprehensive student's guide book have been left incomplete. Another excellent, but expensive work, Curtis's "Genera of British Insects," contains about 250 illustrations and descriptions of flies; but most of these are rather rarities, and the amateur in search of a facile guide to the commoner objects of the country-side will be apt to be disappointed. For the sake of readers possibly eager of advancing further in the study, and in the absence of any commendable guide book, a short appendix has been added to the present work, for help in identifying more numerous species and those of many families and genera not mentioned in the foregoing pages. With the leave of the Northumberland, Durham, and Newcastle-upon-Tyne Natural History Society some valuable plates of illustrations are herewith reprinted, and explanatory notes are added, mainly from the volume of the Society's transactions for 1906, a most valuable work and compilation by the late Rev. W. J. Wingate, of Bishop Auckland. This learned entomologist has succeeded in giving a marvellously comprehensive amount of clear condensed guidance. It is a great privilege that the present booklet has been allowed to borrow from such a source of knowledge, valuable far beyond the locality of its authorship.

Other illustrations which have been borrowed appear with the leave of His Majesty's Office of Works, out of Reports to the Local Government on Public Health and Medical Subjects.

FLY CHART.
Plate I. (APPENDIX)

APPENDIX

INDEX TO TERMS AND SYMBOLS
OF THE
WINGATE FLY CHART, PLATE I.

This Index, together with the following "Table of Wing-cells and Veins," the "Glossary," and plates, II, III, IV, V, VI and VII, will explain the theoretical Diagram entitled The Fly Chart, illustrating characteristic features and exterior parts, by the study of which the reader may learn to differentiate all the sixty families which contain species native to Great Britain.