164 A. J. Jukes-Browne — Division of Upj)er Clialk. 



I replied in the affirmative and pointed out that the establishment of 

 such a zone would bring our zonal arrangement into better accord 

 with that of Germany, where a zone of Scaphites binodosus (containing 

 A. granulatus) had been recognized as separate from the overlying 

 zone of A. quadratus. 



I am surprised that Mr. Brydone should profess to have some 

 doubt about my intention to endorse his proposal and to accept his 

 establishment of a new zone of pilula in Hampshire. What else 

 could I intend wlien I stated that in Table [II " the separate records 

 of the zones of 0. pilula and A. quadratus are based on those given 

 by Messrs. Griffith and Brydone", to whose publication I had 

 previously referred ? 



I did not " quote " from Mr. Brydone's letters nor mention any of 

 the particulars which they conveyed, for that would have been unfair 

 and discourteous ; yet he complains that I ignored " the new grounds 

 on which the proposal was based". The new zone was simply the 

 union of two previously defined subzones, and it sufficed for my 

 pur[)ose to record his intention. How can there possibly be anything 

 unfair in that ? 



He also thinks it was "hardly fair" to have written that the 

 line at the top of the zone of 0. pilula "has not yet been accurately 

 determined in England or France", when I was aware that he had 

 determined it in Hampshire. I admit that my meaning would have 

 been more accurately expressed if I had written that the line had not 

 been determined anj^where in the North of France, nor anywhere in 

 England except in Hants. I present my apologies to Mr. Brydone 

 for appearing to ignore his delimitation of the two zones in Hampshire, 

 but I think most readers must have seen that I was thinking of the 

 large areas over which the line of separation had not been determined, 

 and for which records of the distribution of species were not yet 

 available. 



This brings us to the root of all Mr. Brydone's subsequent criticisms, 

 and that is the value of A. granulatus as a zonal guide. His first 

 remark is that the zone of 0. pilula does not appear as such in all my 

 tables, and that A. granulatus is introduced as if it were an equally 

 good index to the zone as 0. pilula. He feels certain that I intended 

 "to lay it down that the ranges of A. granulatus (u\)\Yards from the 

 Marsiipites zone) and of A quadratus (below the Bel. mucronata zone) 

 corresponded with the two divisions of the old zone of A. quadratus'''' . 



He is, however, mistaken ; I did not intend to make such an 

 assumption, for in Table III I indicated the occasional occurrence 

 of A. quadratus in the zone of O. pilula., where granulatus is the 

 prevalent species. What I did assume was that A. granulatus did 

 not occur in the restricted zone of A. quadratus. and I have yet to 

 learn that it does. Mr. Brydone is at great pains to point out his 

 own mistakes, and to explain that his own record of A. granulatus in 

 the Hampshire zone of 0. pilula is not reliable, but he does not state 

 tliat he has found A. granulatus in the restricted zone of ^. quadratus, 

 either in Hampshire or Sussex. 



I compiled my tables from the most authentic records accessible at 

 the time, and those were the lists published by Mr. Rowe and by 



