EOZOON LIMESTONE OF EASTERN MASSACHUSETTS 539 
meet the objection in this direction which is likely to occur to many 
minds. Dr. Emmons, as most no doubt are aware, endeavored to show 
that limestones occur as intrusive masses as well as in stratified bed 
Commencing my study of the limestones connected with the foliated se- 
ries of rocks in the light of this view, I finally became convinced in 
and during the same year set forth in a series of lectures, that some of 
these limestones have a vein-like structure, and should be regarded as 
true vein-stones. 
Such limestones are to be met with in association with the foliated rocks 
both of eastern and western Vermont, and in various parts of Massa- 
chusetts. They also occur among the Adirondacks. Limestones of this 
character, hand-specimens of which cannot be distinguished by the naked 
eye from specimens of stratified Silurian limestones, are likewise found 
in Vermont and elsewhere in the form of dikes. In most of these cases 
+ 
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e 
vein-like way by gradual deposition extending from the enclosing walls 
toward the centres of what once were cavities. Similar masses of cal- 
careous vein-stone are to be met with in St. Lawrence County, N. Y., 
and in some other places, penetrating beds of sandstone. 
These, and similar cases which might be readily cited, are suited to re- 
move the objection that limestones are always stratified rocks. At the 
same time the occurrence of undoubled Eozoon Canadense in calcareous 
‘vein-stones of eastern Massachusetts tends not only to disprove the an- 
imal origin of the specimens from the localities under consideration, but 
also to involve in doubt the organic character of the Eozoon generally. 
On tHe Eozoon LIMESTONE OF EASTERN MASSACHUSETTS. — By 
Pror. J. B. Perry. : 
Havine about ten years ago, made out that some of the lime- — 
stones associated with the foliated rocks in Vermont and New 
York, are vein-stones, I have eyer been skeptical in regard to the 
supposed organic nature of the Eozoon. As I had more recently 
satisfied myself that limestones in Stoneham, Newbury, and sev- 
eral other places in eastern Massachusetts are also vein-rocks, I at 
once, on the announcement of the discovery of Eozoon in the 
limestones of Newbury, discredited its assumed organic charac- 
ter, on the ground of its occurrence in calcareous masses of a 
vein-like origin. On hearing of a like discovery in Chelmsford, 
and seeing a specimen, I had‘ a similar conviction ; and this I im- 
mediately expressed in one of the lectures which I was then de- 
livering in course, and was able fully to confirm by personal exami- 
nation, on visiting the quarry a few months later, in company with 
my friend Mr. Burbank, of Lowell, who had before and has since 
