iv Preface. 
to publish an illustrated monograph of the group based on these 
collections. 
The Trustees were fortunate in being able to secure the 
services of Mr. F. V. Theobald, M.A. Cantab., who has been 
unremitting in his labours, and has produced the present work 
in a comparatively short space of time. 
It appeared to me to be important, with a view to the 
special object of the work, that numerous text figures should be 
introduced, and that as many species as possible should be 
represented on an enlarged scale in coloured plates. I employed, 
in order to lose as little time as possible in getting the work 
issued to malaria students, a number of different firms of 
lithographers, and stipulated with them for rapid production. 
Mr. Theobald responded with a good will to my request for the 
completion of his work without any avoidable delay, and the 
consequence is that the student of tropical disease has now 
ready for his use a critical monograph of the mosquitoes, to the 
extension, correction, and improvement of which it will certainly 
be one of his main desires to contribute. 
A supplementary volume will be necessary at no distant date 
to record additional species and correct present conclusions. In 
the meanwhile I shall be glad to receive further collections, as 
well as notes and suggestions, with a view to the completion and 
revision of the monograph, from all who have opportunities of 
studying the Culicidae. 
E. Ray Lankester, 
Director. 
British Museum (Nat. Hist.), 
November 23rcl, 1001. 
