188 Correspondence — Mr. Leighton and Mr. Jukes-Browne. 



conclusion of the fifth part of the paper, that " the commencement of 

 the ' epoch ' of the Gault is represented not by the base of the fossil- 

 iferous clays, but by some part of the non-fossiliferous sands now 

 included in the Lower Greensand," is quite valid. Mr. Leighton's 

 discovery of the nodule bed at Westcott proves, however, that the 

 extent to which this is the case was exaggerated in the paper. 

 March 11, 1895. J. W. GregOKT, 



ON PINITES SEXAGONUS, CARRUTHEES. 



Sir, — I desire to correct the statement in the foot-note, relating to 

 my paper at a recent meeting of the Geological Society, referred to on 

 page 102 of Dr. Gregory's paper.^ I said at the meeting that the 

 specimen had been sent to Mr. Carruthers some months before for 

 determination, and that he at once replied (on May 25, 1894) that it 

 appeared to agree with a specimen he had described from the 

 Gault of Eastware Bay, sent to him by Mr. Starkie Gardner, but if 

 I would explain the exact horizon of Mr. Mangles' specimen he would 

 look further into the matter. That I did, and but for unforeseen 

 circumstances Mr Carruthers' note would have been in the hands of 

 the meeting. The species has not yet been determined, but no doubt 

 it is one of those which have been recorded from the Gault. 



I think it is a pity that Dr. Gregory has included unfossiliferous 

 beds, about which we have no relative evidence, in the table on 

 page 100 of his paper. Of course, if we were under obligation to 

 divide the Lower Greensand into divisions, fossils or no fossils, the 

 Survey classification could be retained by simply placing the Leith 

 Hill Cherts and Dorking Clayey Sands, into which they pass, in the 

 Sandgate Beds. As to the latter of these (the Clayey Sands), this 

 was suggested in 1892 by Professor Boulger and myself, and two 

 years later by Mr. F. Chapman. Were it necessary, other difficulties 

 brought out by detailed mapping could be similarly dealt with. 

 Looking at Dr. Gregory's table, one is inclined to enquire, since he 

 deals with the Leith Hill Cherts, where the Eeigate-Tilburstow Hill 

 Cherts are to be placed ? Thos. Leighton. 



March 5, 1895. 



GAULT AND LOWER GREENSAND. 

 Sir, — Dr. Gregory's paper on some fossils from the Lower 

 Greensand of Great Chart, in Kent, is a welcome contribution to 

 the classification of the Lower Cretaceous series of the Wealden 

 area. His views with regard to the general grouping together of 

 the Sandgate Beds, Bargate Beds, Fuller's Earth, and Farringdon 

 Beds coincide with a conclusion I came to some years ago. His 

 subdivision of the whole series into three instead of four, and his 

 correlation of the two upper groups — the (1) Folkestone and 

 Sandgate, and (2) the Hythe Beds — with the Aptian of the continent, 

 is exactly the arrangement I suggested in this Magazine nine 

 years ago.^ 



1 Geol. Mag. March 1895. 



2 Gbol. Mag. 1886, Dec. III. Vol. III. p. 316 et seq. 



