116 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. [DcC. 23, 



structure of the latter is similar to tliat of the Canadian rock con- 

 taining the so-called Eozoon. 



The authors then proceeded to treat of the supposed foraminiferal 

 characters of "Eozoon." Eirst, as to the " cell-wall" or "nummu- 

 line layer," they advanced repeated evidence of the value of their 

 former proofs that the typical form is due to aciculate serpentine 

 (or modified chrysotile) of inorganic origin — having examined, be- 

 sides others, a Canadian specimen presented by Dr. Carpenter. 

 Secondly, nothing new was adduced with regard to the mineral 

 structure of the so-called " intermediate skeleton." Thirdly, in proof 

 that the " chamber- casts" are not of organic origin, the authors 

 referred to their former work, and stated that chondrodite and pyral- 

 lolite may be added to the list of minerals that occur, as such, disse- 

 minated in limestones. They thought it strange that a carbonate, 

 as well as a silicate, should not have been found filling the so-called 

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

 men 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 instances 

 of this mineral being an infilhng. Fourthly, reiterating their ob- 

 servations 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 pre- 

 sence 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 the authors 

 had not been able to confirm the accuracy of the observations in these 

 cases, having examined a Canadian specimen, presented by Dr. Car- 

 penter 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. Mineralogical consi- 

 derations of Eozoonal rocks were next entered upon ; and from the 

 study of Canadian specimens, and of others from Connemara and 

 Bavaria, 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 pseudomorphic after one 

 or other form of serpentine by in^ltration and replacement. The 

 rounded form of the granular masses of chondrodite, coccolite, &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 



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