Dr. W. B. Carpenter on Eozoon cauadeuse. 465 



either to show that the true Eozoic structure has been fre- 

 quently altered by mineral metamoqjhism, or to adduce the 

 occurrence of Ophites more or less resembling the Eozoon of 

 the Canadian Laurentians at various subsequent Geological 

 epochs. The existence of any number or variety of purely 

 mineral Ophites would not disprove the organic origin of the 

 Canadian Eozoon — unless it could be shown that some wonder- 

 ful process of mineralization is competent to constnict not 

 only its multiplied alternating lamellae of Calcite and Serpen- 

 tine, the dencbitic extensions of the latter into the former, 

 and the " acicular layer " of decalcified specimens, but (1) the 

 pre-existing canalization of the calcareous lamellae, (2) the 

 unfilled nuvimuline tubulation of the proper wall of the 

 chambers, and (3) the peculiar calcarine relation of the canali- 

 zation and tubulation, here described and figured from speci- 

 mens in the highest state of preservation, showing the least 

 evidence of any mineral change. 



On the other hand, Professors King and Rowney began 

 their studies of Eozoic structure upon the Galway Ophite — a 

 rock which Sir Roderick JMurchison described to me at the 

 time as having been so much ^' tumbled about," that he was 

 not at all sure of its geological position, and which exhibits 

 such obvious evidences of mineralization, with such an entire 

 absence of any vestige of organic structure, that I should never 

 for a moment have thought of crediting it with an organic 

 origin, but for the general resemblance of its Sei-pentine-grains 

 to those of the " acervuline" portion of the Canadian Eozoon. 

 They pronoimced with the most positive certainty upon the 

 Mineral origin of the Canadian Eozoon, before they had sub- 

 jected transparent sections of it to any of that careful compari- 

 son with similar sections of recent Foraminifera, which had 

 been the basis of Dr. Dawson's original determination, and of 

 my own subsequent confirmation, of its organic structure. And 

 while Prof. Rowney never laid claim to any knowledge of 

 Micro-Palaiontology, the accuracy of Prof. King's information 

 in this department of inquiry may be estimated by the fact, 

 that when (about the same time) he made his first acquaint- 

 ance with the Orhulina universa brought up in the ' Porcu- 

 pine' somidings off the West of Ireland, he forthwith described 

 them as not improbably affording the explanation of the gra- 

 nular concretionary structure of Oolites. — That I did not shrink 

 (as is imputed to me in Profs. King and Rowney's last com- 

 munication) from meeting them in their own selected field, 

 will appear from the following statement. 



When, about five years since, the Galway Professors j)rc- 

 scntcd their Memoir on Eozoon to the Royal Irish Academy, 



