VI PREFACE. 



the date about which any particular volume would be 

 ready for distribution to the subscribers. 



The present volume is almost twice the size of any 

 of its predecessors, but it was thought inadvisable to 

 divide it, because in that case a considerably smaller 

 proportion of plates would have been available for 

 each volume. 



As for previous volumes, Mr. G, C. Bignell has 

 compiled the lists of parasites ; and I have also to 

 again thank Mr. W. Denison Roebuck for the as- 

 sistance he has rendered me in the editing of the five 

 volumes with which I have been connected. 



GEO. T. PORRITT. 



Crosland Hall, 



huddersfield ; 



December, 1900. 



