[ 188 ] 



XXIV. Proceedings of Learned Societi.es. 



GEOLOGICAL SOCIETY. 

 [Continued from Vol. ix. p. 818.] 



April 5th, 1905.— J. E. Marr, Sc.D., E.R.S., President, 

 in the Chair. 



r PHE following communications were read: — 



1. ' On the Divisions and Correlation of the Upper Portion of 

 the Coal-Measures, with special reference to their Development 

 in the Midland Counties of England.' By llobert Kidston, 

 E.RS.L. & E., F.G.S. 



2. ' On the Age and Relations of the Phosphatic Chalk of 

 Taplow.' By Harold J. Osborne White, F.G.S., and Llewellyn 

 Treacher, E.G.S. 



The paper opens with an account of the work hitherto accom- 

 plished in the Phosphatic Chalk of Taplow, and especially of the 

 work of Mr. Strahan. The rocks at this locality are then described 

 in detail, and the following classification is adopted : — 



Feet. 



E. Upper White Chalk (visible) 16 



I). Upper Brown Chalk, or rich phosphatic band about 8 



C. Middle White Chalk „ 16 



B. Lower Brown Chalk, or rich phosphatic band ,, 4 

 A. Lower White Chalk ,, (visible) 17 



The Lower White Chalk includes a thin layer of tabular flint 

 and one of elongated nodular flints, and the first signs of phosphatic 

 material were observed a few inches below the tabular seam. 

 Attention is drawn to the presence of phosphatic nodules and 

 concretions at certain horizons. Eossil-iists are given from each of 

 the above divisions ; and the authors conclude that the Lower White 

 Chalk belongs to the zone of Micraster cor-anyuinum, and the 

 succeeding beds to that of Ma rsujrites testadwarius ; while the 

 lower phosphate-band represents the lower part of the Uintacrinus- 

 band, and the upper one that of the Marsujntes-hand of that zone. 

 In each phosphate-band the base is quite sharp, being defined by a 

 rock-bed in the Chalk ; but the upper limit is very ill-marked. The 

 Middle White Chalk is in part divided into lcnticles with sliekensided 

 surfaces. The authors find Actinocamacc verus in B, and A. yranidatus 

 in D and E, but not A. quadratus in any bed. Phosphatization is 

 not confined to the foraminifera, and other microscopic remains, 

 but occurs in all shells and structures which are readily penetrable, 

 although not so markedly in those of a more homogeneous character. 

 Scalaria occurs in division E, the upper part of which may possibly 

 just include the base of the zone of Actinocamacc quadratus, or at 

 any rate may not be many feet below that base. The distribution, 



