70 INTRODUCTION. 



specimens as far as requisite, and to recognise some forms that had not been 

 published in Part I. 



Other sources of information have been several selected examples of Crag, 

 collected by Professor Prestwich from the " Zones" defined by himself in 1871, 

 and other samples specially taken from the several zones by Mr. H. W. Burrows. 

 Long conversant with the fossils of the Crag, and with the Foraminifera in 

 particular, Mr. Burrows, in co-operation with Mr. R. Holland, has worked assidu- 

 ously on these microzoa ; and they now enrich this Monograph with the results, 

 both by excellent figures of the Foraminifera shown in Plates VI and VII, by the 

 notes throughout this Part of the Monograph on the geographical and geological 

 distribution of the several species, and by Tables of the genera and species. Mr. 

 Burrows has also contributed the valuable stratigraphical notes on the divisions of 

 the Crag. Other courteous and obliging friends — namely, Mr. C. D. Sherborn, 

 Mr. F. W. Millett, and Mr. F. Chapman — have given valuable help in several ways 

 in determining the relationship of the forms, and their bibliography and synonymy. 



Plate V contains many of the forms selected from the old collections, which, 

 after having been photographed, were lithographed, in company with some from 

 Mr. Millett's and Mr. Chapman's collections, by Messrs. George West and Sons, 

 with their usual conscientious exactitude. Plates VI and VII were lithographed 

 by them from drawings kindly made by Messrs. Burrows and Holland, from 

 specimens which, with the few exceptions noted in the Explanations of the Plates, 

 are from their own collections, and have not been previously recorded from the 

 Crag. 



