CONTEMPORARIKS OF EOZOON 1 9/ 



aceous fragments which afford more or less evidence 

 of organic origin. The contents of these organic 

 limestones may be considered under the following 

 heads : — 



1. Remains of Eozoon. 



2. Other calcareous bodies, probably organic. 



3. Objects imbedded in the serpentine. 



4. Carbonaceous matters. 



"(i) The more perfect individuals of Eozoon do 

 not constitute the mass of any of the larger speci- 

 mens in our collections ; but considerable portions 

 of some of them are made up of material of similar 

 minute structure, destitute of lamination, and irregu- 

 larly arranged. Some of this material gives the im- 

 pression that there may have been organisms similar 

 to Eozoon, but growing in an irregular or acervuline 

 manner without lamination. Of this, however, I 

 cannot be certain ; and, on the other hand, there is 

 distinct evidence of the aggregation of fragments of 

 Eozoon in some of these specimens. In some they 

 constitute the greater part of the mass. In others 

 they are imbedded in calcareous matter of a different 

 character, or in serpentine or granular pyroxene. In 

 most of the specimens the cells of the fossils are 

 more or less filled with these minerals ; and in some 



