Dr. W. B, Carpenter on Eozoon Caiiadense. 137 



reoiis and Siliceous minerals, often amounting to fifty or more of 

 each kind, extending througli a great range of area, nor of the 

 fact that not only is this arrangement the same, though the sili- 

 ceous mineral may be Serpentine in one place. Pyroxene in an- 

 other, or Loganite in another, whilst the calcareous may be Calcite 

 in one part and Dolomite in another, but that these variations 

 may occur in one and the same specimen, the structural arrange- 

 ment being continuous throughout. 



And in wliat they state of the peculiar lamella forming the 

 proper wall of the chambers, which I have designated the " num- 

 muliue layer," they have fallen into errors of fact so remarkable, 

 that I can only account for them by the belief that when their 

 paper was written they knew this layer only by decalcified speci- 

 mens, and had never seen it in thin transparent sections. For 

 they describe it as composed of parallel fibres of chrysotile packed 

 together without any intermediate substance ; whereas I have 

 distinctly proved that the siliceous fibres are imbedded in a calca- 

 reous matrix, which I therefore feel justified in regarding as a 

 finely tubulated Nummuline shell, of which the tubuli that were 

 originally occupied by pseudopodia have been permeated by sili- 

 ceous infiltration. 



So, again, while asserting that by no conceivable process could 

 the animal substance originally occupying these tubuli have been 

 replaced by siliceous minerals, they have entirely ignored the fact 

 stated by me, that this very replacement has taken place in recent 

 specimens in my possession — a fact on the basis of which the 

 reconstruction of the animal of Eozoon proposed by Dr. Dawson 

 and myself securely rests. 



The question may now, I believe, be regarded as conclusively 

 settled by the recent discovery, in a sedimentary limestone of the 

 Lower Laureutian formation at Tudor in Canada, of a specimen 

 oi Eozoon presenting characters that cannot, in the opinion of the 

 most experienced palaeontologists and mineralogists, be accounted 

 for on any other hypothesis than that of its organic origin. For, 

 in the first place, the occurrence of a calcareous framework or 

 skeleton in a matrix of sedimentary limestone, which also fills up 

 its interspaces, altogether excludes the hypothesis that this frame- 

 work might be the product of any kind of psevidomorphic arrange- 

 ment produced by tlie separation of calcareous and siliceous 

 minerals from a solution containing both. And, secondly, this 

 specimen exhibits that which had not previously been distinctly 

 seen in any other, viz. a distinctly limited contour, formed by 

 the curving downwards and closing-in of the septa, in a manner 

 as perfect and characteristic as the closing-in of the successive 

 chambers of any polythalamous shell. I believe that no palaeonto- 

 logist familiar with Palaeozoic fossils would have hesitated to pro- 

 nounce this specimen a fossil Coral allied to Stromatopora, if it 

 had occurred in a Silurian Limestone. 



That this specimen, though diftering greatly in appearance 



