CONTENTS 



Page 



Illustrations viii 



Explanation of collectors' initials x 



Introduction 1 



The external morphology of the Diptera 10 



Variations in size 10 



Variations in form and structure 10 



Morphology of the head and its appendages 12 



Morphology of the thorax and its appendages 41 



Morphology of the abdomen and its appendages 67 



Phylogenetic conclusions 115 



Bibliography 119 



Abbreviations 132 



Taxonomy 166 



Wing venation 166 



Key to families 175 



Tanyderidae 183 



Ptychopteridae ^. 184 



Trichoceridae 188 



Anisopodidae 192 



Tipulidae 196 



Index 487 



Morphology 487 



Taxonomy 501 





