250 Dawson and Carpenter on Eozoon Canadense. 
ble of showing the general form. I may explain, in reference 
to this, that long practice in the examination of these lime 
stones has enabled me to detect the smallest fragments of — 
Eozoon when present, and that in this way I had ascertained 
the existence of this fossil in one of the limestones of Madoc 
before the discovery of the fine specimen now under conside- 
ration. 
I am disposed to regard the present specimen asa young in- 
dividual, broken from its attachment and imbedded in a sandy 
calcareous mud. Its discovery affords the hope that the com- 
paratively unaltered sediments in which it has been preserved 
and which also contain the worm-burrows described by me m 
the ‘Quarterly Journal of the Geological Society’ for Novem- 
cal will hereafter still more largely illustrate the Laurentian 
auna. 
a eae WIRES boy Gein 2 a ean an ee ey OR ae 
II SPECIMENS FROM LONG LAKE AND WENTWORTH. 
Specimens from Long Lake, in the collection of the Geo- 
logical Survey of Canada, exhibit white crystalime limestone 
with light green compact or septariifo ntine, 
nder the microscope the calcareous matter present a 
an example of acervuline Zozoon but rather of fragments ot . 
the interstices and cell-cavities filled with serpentine. pe 
not found in any of these fragments a canal-system 
to that of Hozoon Canadense, though there are casts pie 
stolons, and, under a high power, the calcareous 
shows in many places the peculiar granular or meer 
pearance which is one of the characters of the a 
skeleton of that species, In a few places a tubula 
or with structure similar to that of Hoaoon | 
e. i | 
Specimens of Laurentian limestone from Wentworth in 4 
collection of the Geological Survey, exhibit map y of sand, 4 
siliceous bodies, some of which are apparently eevee the 
or small pebbles ; but others, especially when freed i 
d having minute vermicular processé 1 
from their surfaces (Pl. III, fig. 3). At first 7 je not a 
gest the idea of spicules ; but I think it on the W! a 
* Vol. xxii, p. 608. 
t I use the term ‘septariiform’ to denote the curdled appearance 
sented by the Laurentian serpentine, 
go often PD 
