



PREFACE 



The present volume is the second one supplementary to Mr. 

 Theobald's original work on the Culicidse, in two volumes, with 

 an atlas of plates, published by the Trustees in 1901. As was 

 to be anticipated, the first publication of a systematic treatise 

 on the blood-sucking gnats, and the sending of requests to all 

 parts of the world for specimens, have resulted in an enormous 

 and rapid increase of knowledge. The first two volumes (the 

 original work), published in 1901, described 289 species, of which 

 114 were new to science, and was based on a collection of about 

 5,000 specimens. The first supplementary volume (Vol. III.) 

 described numerous additional species, of which 88 were for the 

 first time described in that volume. It was based on additional 

 collections received since the completion of the original work, 

 numbering 4,200 specimens. The present volume (Vol. IV., 

 second supplementary volume) includes 160 species described 

 since 1903, when the last volume went to press. Seventy-three 

 additional species are described in this volume for the first time. 

 About 12,000 specimens have been received in this Museum 

 since 1903, but it has not been- ppss^ble to examine more than 

 half that number for report in the present volume. A fifth 

 volume (third supplementary volume) is in active preparation. 



The importance of the accurate study and discrimination of 

 the various species of insects which suck the blood or other 

 j uices of man and animals, and may thus i become carriers of 

 disease-producing parasites, has determined the Trustees of the 

 British Museum to endeavour to obtain as complete collections 

 as possible of blood-sucking insects and arachnids from all parts 

 of the world, with a view to the production of further mono- 

 graphs on such flies, fleas, bugs, lice, ticks and acarids as may 

 be agents in the spread of disease. 



In carrying out such a task there is no reason why the 

 British Museum should undertake every section, and it is to be 



