On Eozoin Canadense. 361 
rs 
show ay a microscope the characteristic spiral arrangement 
of the cel 
“Tt out phage ms from these pepsin: that glauconite 
is formed by chemical reactions in the ooze at the bottom of the 
sea, where ainsi silica comes in scan with iron-oxyd ren- 
dered soluble by organic matter; the resulting silicate deposits 
itself in cavities of shells and other vacant spaces. ocess 
analogous to this in its results, has filled the chambers es canals 
oD 
of the Eozoén, or rather of its replacing silicates, are by no 
means ve least important points in the history of this remark- 
able foss 
Explanation of the Plate illustrating the Structure and Affinities of 
Eozoin Canedense. 
Of the figures here given, 1, 3, 64, 64, and 7, are selected 
from two plates given by Dr. Carpenter to illustrate his paper; 
while 2, 4, and 5, are from the plates accompanying Dr. Daw- 
son’s descript tion, and are from drawings by Mr. Homes H. 
Smith, the artist of the Canadian Geological Survey. 
The figures, with the exception of 7, are from transparent 
Sections of ia pele in which the original shell was well pre- 
served, and its minutest cavities infiltrated with serpentine. 
Figure 7 is to a specimen from which the calcareous skeleton — 
‘was removed by an acid, and represents the internal casts of t 
tubes, as seen by reflected light. 
Fig. 1. Vertical section of regularly stratified teodines of FHozoin show- 
ing the ordinarily continuous connection of the ch hambers 
each stratum; a. enified 10 diam ithe 
2: Horizontal section of _ n from Reset magnified 25... 
a proper wells of eheit a ee bb the in 
* Report of United States Coast Survey, comet 
