LIST OF ILLUSTBATIOm 
PLATES. 
I. Chart showing mean monthly Water-level in 
Wells at Barley and Odsey. To face p. 22 
II. Map showing the area affected by the Meteorite 
of the 20th of November, 1887 .. Between pp. 32 & 33 
III. Map of Hertfordshire showing its Climatological 
Stations. To face p. 203 
WOODCUTS. 
Diagram-section of a Pit near Bennet’s End .. . . p. xxxvii 
Section through Totternhoe Knoll and Kensworth 
Hill, near Dunstable . p. xliii 
Walckena'erainterjecta } sp. nov. p. 18 
