PREFACE. 
' I X HE coloured drawings from which the plates in this book are 
reproduced have been prepared for exhibition in the Nortli Hall 
of this Museum. 
Before devoting them, however, to the purpose for which they 
were primarily intended, it was thought that if published in a con- 
venient form their sphere of usefulness would be increased, while an 
opportunity would also be afforded for the inclusion of fuller notes on 
each species than can be given in a label. 
For exhibition purposes, and to facilitate the recognition and 
comparison of the different species, the drawings have been made on 
a greatly enlarged scale, to which it has not in all cases been possible 
to adhere in the reproductions ; but wherever practicable the copies 
are of the same size as the originals. 
Many of the species here illustrated have an extremely wide dis- 
tribution, so that the book may perhaps be of service to naturalists 
outside the British Islands ; while the illustrations, either as repre- 
senting species or simply as types of genera, will doubtless be useful 
to those engaged in the study of Blood-Sucking Flies in connection 
with disease. 
E. RAY LANKESTER. 
British Museum (Natural History), 
Cromwell Road, London, S.W. 
March 24th, 1906. 
