Dr. W. B. Carpenter on Eozoon Canadense. 137 
reous and Siliceous minerals, often amounting to fifty or more of 
each kind, extending through 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 what they state of the peculiar lamella forming-the 
proper wall of the chambers, which [ have designated the “ num- 
muline 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the animal substance originally occupying these tubuli have been 
replaced by siliceous minerals, they have entirely ignored the fact 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 Laurentian formation at Tudor in Canada, of a specimen 
of Hozoon presenting characters that cannot, in the opinion of the 
most experienced paleontologists 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 pseudomorphie arrange- 
ment produced by the separation of caleareous 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 paleonto- 
logist familiar with Paleozoic 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 differing greatly in appearance 
