xii Introduction 



press by myself. I therefore beg the indulgence of those who use this 

 book for any errors of omission or commission that may occur, And 

 as the whole work will take some years to go through the press a 

 note of any such errors will be specially valuable for inclusion as we 

 proceed or in the final part, in the same way as such information 

 received since the issue of my first volume has been duly recorded in 

 the proper order herein. 



C. DAVIES SHERBORN. 



British Museum (Natural History), 

 london, s.w. 7. 



October 192 1. 



