in the South English Chalk. 



407 



These measurements compare very curiously with Dr. Rowe's, 

 which were — 



ft. in. 

 Uintacrinus band . . . . . . . . 34 6 



Marsupites band ( = my zone of Marsupites) . . . 47 

 Zone of A. qiiadratus (= my zones of 0. pilula and 



A. quadrat us combined) ....... 343 



423 6 



It will be seen that our grand totals differ by less than 7 per cent, 

 yet our totals for the Uintacrinus band and for the Marsupites zone or 

 band differ much more largely, so that it is probable that our lower 

 and upper boundaries of these items are placed in very different 

 positions. Unfortunately Dr. Rowe does not give any indications by 

 which the points at which he fixed these boundaries can be identified 

 in the field, and no close comparison can be made. The same difficulty 

 has repeatedly confronted me in trying to compare my results in 

 Dorset with those obtained by Dr. Kowe, and I have therefore 

 thought it desirable to give in each case summarized sections with 

 sufficient details concerning all indications of boundaries on which 

 I have relied to enable subsequent workers to identify them in the 

 field and use any records of mine which maj' fill lacunae in their own. 

 In these sections I have aimed at mentioning every definite marl 

 seam and flint tabular met with, and I believe that with their aid 

 any desired point can be readily picked out. Flint seams are to be 

 assumed to occur at frequent intervals unless otherwise stated. 



The following section is intended to serve the above purpose for 

 Scratchells Bay. 



East End of Mucronata Fall at Beach Level. 



-r, , t Chalk with two marl seams 



B. inucronata.) 



Marl seam marking probably the boundary 



of the-inucronata zone fixed by Dr. Eowe. 



Chalk .... 



Marl seam. 

 Chalk with a flint tabular . 



Marl seam. 

 Chalk with a flint tabular . 



Marl seam. 

 Chalk .... 



Chalk with three marl seams 

 Chalk .... 



Marl seam. 

 Chalk with a red sponge bed 



Marl seam. 

 Chalk with six marl seams . 



Marl seam. 

 Chalk .... 



Flint seam. 

 VChalk .... 



Carried forward 



216 6 



