THE PEESERVATION OP EOZOON. 



125 



jcording to Giimbel, present the same connecting cylinders 

 bnd branching stems as the pargasite, and are by him supposed 

 have been moulded in the same manner. . . . Yery 

 lutiful evidences of the same organic structure consisting 

 )f the casts of tubuli and their ramifications, were also ob- 

 served by Giimbel in a purely crystalline limestone, enclosing 



[•anules of chondrodite, hornblende, and garnet, from Boden 

 Saxony. Other specimens of limestone, both with and 



rithout serpentine and chondrodite, were examined with- 

 )ut exhibiting any traces of these peculiar forms ; and these 

 legative results are justly deemed by Giimbel as going to 

 )rove that the structure of the others is really, like that of 



lozoon, the result of the intervention of organic forms. 



besides the minerals observed in the replacing substance of 



lozoon in Canada, viz., serpentine, pyroxene, and loganite, 



riimbel adds chondrodite, hornblende, scapolite, and probably 



Iso pyrallolite, quartz, iolite, and dichroite." 



(D.) Glauconites. 



The following is from a paper by Dr. Hunt in the Report of 

 [the Survey of Canada for 1866 : — 



In connection with the Eozoon it is interesting to examine 



lore carefully into the nature of the matters which have been 



[called glauconite or green-sand. These names have been 



;iven to substances of unlike composition, which, however, 



toccur under similar conditions, and appear to be chemical 



leposits from water, filling cavities in minute fossils, or 



forming grains in sedimentary rocks of various ages. Al- 



|though greenish in colour, and soft and earthy in texture, it 



will be seen that the various glauconites difier widely in 



[composition. The variety best known, and commonly regarded 



[as the type of the glauconites, is that found in the green-sand of 



Cretaceous age in New Jersey, and in the Tertiary of Alabama ; 



[the glauconite from the Lower Silurian rocks of the Upper 



^Mississippi is identical with it in composition. Analysis 



[shows these glauconites to be essentially hydrous silicates of 



mrotoxyd of iron, with more or less alumina, and small but 



