538 EOZOON CANADENSE. 
wall” of Eozoon as I have seen it in the Canadian specimens. 
The surfaces of many of the grains are covered with acicular crys- 
tals penetrating the calcite. Some of these, as they extend into 
the calcite, become rounded and curved, losing the acicular 
character. 
In nearly all the specimens examined, bundles of acicular fibres, 
apparently of tremolite, are scattered abundantly in the calcite. 
n some portions of the rock the serpentine appears embedded 
in the limestone in definite crystalline forms, apparently pseudo- 
morphs of chrysolite, or boltonite. In the quarries of Boxboro 
and Carlisle, cinnamon garnet is abundant, associated with scap- 
olite and green pyroxene or coccolite, with calcite. L have exam- 
ined the calcite of many of these specimens for traces of. the 
eozoonal structure, but, so far, with negative results. In fact, so 
far as I have observed, the tubuli invariably occur in the rock as- 
sociated with serpentine. 
Some facts have been stated in this communication for which 
I offer no theories in explanation. I do not claim a sufficient 
knowledge of the Foraminifera to found any argument upon the 
microscopic appearances that I have observed, nor do I mean now 
to enter into a discussion of the general question as to the true 
character of the Hozoon Canadense, as described by Carpenter 
and Dawson. 
I am unable, however, to reconcile the facts here stated with — 
the theory that the form in these rocks which have been identi- 
fied as belonging to the structure of Eozoon, are of organic origin. 
On the other hand, it appears to me not unreasonable to infer 
that the so-called “tubuli” that are so abundant in these rocks, 
are semi-crystalline forms that have been deposited with the serpen- 
tine and other minerals on the walls of the cavities, by infiltration 
of waters charged with mineral matters. 
Professor Perry said :—I desire to bear testimony to the PARA cor- 
rectness of the statements made by Mr. Burbank. 
Tn addition to the evidence given by hin, I would refer tothe fact that 
the limestones under consideration cpt ee with breaks and 
other irregularities in the enclo. osing mass of gnei I may also state 
that in some places calcareous veins which Diny. aronended from the 
main masses of limestone, may be seen ramifying portions of the walls 
that form the cavities. 
As geologists have generally supposed that all thnaa are stratified 
rocks, a few words may be needful on this point, especially, as serving to 
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