236 Geological Society : — Messrs. Rowney and King on the 



chambers ; and they decidedly refused to accept the Tudor spe- 

 cimen having some tubuli filled with calcite, to which they suppose 

 Dawson refers when speaking of chambers filled with calcite, as 

 a case in point ; they were unacquainted with any published in- 

 stances of this mineral being an infilling. Fourthly, reiterating 

 their observations on the so-called " canal-system," they suggested 

 that the globoso-vermicular bodies noticed by Dawson and Giimbel 

 may be metaxite ; and they insisted on the difficulty of explaining 

 the presence of isolated unbroken tube -casts in patches of pure 

 limestone. The Madoc specimen, described by Dawson as having its 

 " canals" and " chambers" filled with calcite, was next referred to ; 

 and it was argued that the so-called calcite, both in this and in 

 another specimen, described by Carpenter, is doubtful and not 

 proved ; for they had not been able to confirm the accuracy of the 

 observations in these cases, having examined a Canadian specimen, 

 presented by Dr. Carpenter as an example of the kind, which had in 

 it "homogeneous and structureless forms of the canal-system" that 

 were not dissolved in the decalcification. Fifthly, the organic nature 

 of the so-called " stolons" was regarded as quite disproved. Minera- 

 logical considerations of Eozoonal rocks were next entered upon ; 

 and from the study of Canadian specimens, and of others from Con- 

 nemara and Neybiggen (*?), described in full, the authors concluded 

 that they fully prove the " canal-system," " chamber-casts," and 

 " nummuline layer " to be structural and inorganic modifications of 

 serpentine — that the whole have originated from the change or waste 

 of granules, plates, &c. of serpentine ; and they incline to the belief 

 that the calcite of the " intermediate skeleton " is j)seudomorphic 

 after one or other form of serpentine by infiltration and replacement. 

 The rounded form of the granular masses of chondrodite, cocco- 

 lite, &c. in some limestones was also referred by the authors to the 

 gradual removal of their surfaces by deep-seated hydrothermal 

 agency. 



It was then argued that the organic nature of Eozoon cannot be 

 supported by the cumulative evidence afforded by the combination 

 of foraminiferal features ; for these features, combined and due to 

 purely mineral paragenesis, had occurred to the authors in certain 

 ophites, though some are wanting in other ophites, just as they 

 are not always present in the Eozoonal rock of Canada. 



Serpentine has been described as having been deposited in the 

 cavities of Eozoon, and having taken the place of its sarcode ; but 

 the authors criticised all the quoted analogies of such a precipitation 

 of any siliceo-magnesian substance, disbelieved them, and put aside 

 glauconitic infiltration as beside the question. 



Considered geologically, with reference to its occurrence in a 

 metamorphic rock, the authors regarded the Eozoon as an organic 

 impossibility ; and they asked why it should never be found in any- 

 thing but crystalline or semicrystalline rocks — in ophites or ophi- 

 calcites of widely different ages. Particularly they found eozoonal 

 structure in the Liassic ophite of Skye ; and this they described in full. 

 They criticised Sterry Hunt's change of opinion, who used to think 



