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XVIII. Proceedings of Learned Societies. 



GEOLOGICAL SOCIETY. 

 [Continued from vol. xlv. p. 462.] 

 December 18, 1872.— Warington W. Smyth, Esq., F.R.S., Vice- 

 President, in the Chair. 

 rPHE following communications were read : — 

 - 1 - 1. " Further Notes on the Punfield Section." By C. J. A. Meyer, 

 Esq.,F.G.S. 



This paper was supplementary to one read before the Society by 

 the author in March of the present year (see Quart. Journ. Geol. 

 Soc. xxviii. p. 245), and contained the results of a fresh examination 

 of the section at Punfield, and of the Wealden and Neocomian strata 

 of the Isle of Wight. He described the section exposed at his visit 

 to Punfield as presenting : — ] . True Wealden beds ; 2. a grit-bed 

 with limestone and paper-shales, containing fish-bones and Cyprides ; 

 3. apparently argillaceous beds ; 4. a thin band of hard ferruginous 

 sandstone with Atherfield fossils ; 5. a clay-bed, the upper part re- 

 garded as representing the " lobster-clay " of Atherfield, the lower 

 sandy portion containing an abundance of marine fossils belonging 

 to common Atherfield species; 6. the so-called "marine band;" and 

 7. laminated clays and sands with lignite. The author indicated 

 the accordance of this arrangement with what is observed elsewhere, 

 and maintained that the grit-bed (No. 2), with its limestone and paper- 

 shales, containing Cypris and Cyrena, was really to be regarded as 

 the passage-bed between the Wealden and the Neocomian. 



2. " On the Coprolites of the Upper Greensand Formation, and on 

 Flints." By W. Johnson Sollas, Esq. 



The first part of this paper was principally occupied in an endea- 

 vour to explain the perfect fossilization of sponges and other soft- 

 bodied animals. It was shown that the hypothesis which considered 

 that sponges had become silicified by an attraction of their spicules for 

 silica was altogether untenable. Mr. Hawkins Johnson's supposititious 

 reaction, according to which the carbon of animal matter is directly 

 replaced by silicon, was shown to be inconsistent with the known 

 facts of chemistry. The author's explanation was not intended to 

 be final. The first fact pointed out was the very remarkable way 

 in which the silica or calcic phosphate of the fossils under considera- 

 tion followed the former extension of organic matter. This was ex- 

 plained for silica by the fact that, when silicic acid is added to such 

 animal matters as albumen or gelatin, it forms with them a definite 

 chemical compound ; and it was assumed that in process of time this 

 highly complex organic substance would decompose, its organic con- 

 stituents would be evolved, and its silica would remain behind. In 

 such a way flints might be produced ; and dialysis would lend its aid. 

 The same explanation was applied to account for the connexion 

 between calcic phosphate and animal matter in the case of the 

 " Coprolites." 



