550 BULLETIN OF THE NATURAL HISTORY SOCIETY. 
of these columns, this space being (partly) filled with an irregular 
and Broken calcareous or calcareo-magnesian deposit. 
“ The microscopic character of these columns and the layers 
has not been studied, but to the naked eye the more dolomitic 
layers, when well preserved, are distinctly beaded, as if they were 
filled up chambers of an organism in which the chambers were 
imperfectly separated from each other. 
“A peculiarity of this object is that of the sudden cessation 
cf growth, either of a part, or of the whole, of an individual 
column. In a case of this kind the space thus left vacant is 
occupied by the extension over it of the layers of a neighboring 
column, or by the growth of one or more new individuals on the 
senile surface. 
“ These new columns have in all cases a dome-shaped or hemi- 
spherical form, which they retain until they are as large, or larger, 
than a finger-end, after which the layers begin to flatten. 
“ There is a fossil described by Professor James Hall ( Crypto - 
zoon proliferum) occurring in the Calciferous rocks at Green- 
field, N. Y., which at first glance strikingly resembles the Acadian 
fossil above described,* but it differs in the mode of growth, as 
it consists of rosettes of various sizes, consisting of concave 
laminae (while those of Archaeozoon Acadiense are convex).” 
This is all that was published about this peculiar fossil at the 
time it was first investigated. But two years afterward Dr. W. 
D. Matthew, then a fellow of Columbia College, New York, 
undertook an examination of the “ Crystal. ine rocks near St. 
John,” and in the course of his investigations met with this fossil 
in the limestones of the “ Upper Series ” in the peninsula north 
of the city of St. John, on the shore of the “Narrows” of the 
St. John river. f The locality is in the same basin of limestones 
as that containing the typical forms from Green Head. 
In 1894 another locality for this fossil was discovered by Mr. 
Geoffrey Stead on Douglas avenue, on the ridge between the 
harbor of St. John and the river St. John above the “Falls.” The 
fossil here is not quite at the base of the limestone, but is not far 
from it, and the individuals are smaller than many of those seen 
• See 36th Ann. Rep. N. Y. State Mus, Appendix. 
Nat. Hist. Soc. of N. Bruns’k, Bull. XII, p. 16. 
