126 Scientific Proceedings, Royal Dublin Society. 



A great deal of the olivine sand is of the finest possible [grain] ; 

 indeed it is often so fine that although a much heavier mineral 

 than carbonate of lime, it will often, where both are washed by the 

 waves, settle on the top of the coral sand, and I have often scraped 

 the almost pure fine olivine sand from the top of a coral sand 

 beach. This mixture of the two sands is common over the group, 

 extending 400 miles from Hawaii to Bird Island." Again, "... 

 there is every grade of mixture from all coral to all olivine. Yery 

 often the olivine sand rock will be found to run in streaks amongst 

 the coral sand rock, so that in the course of time, when the coral 

 sand rock comes to be metamorphosed into a limestone or a marble, 

 the olivine sand rock would probably suffer the change which that 

 mineral is well-known to experience, namely into serpentine." 



These views will certainly commend themselves to many of 

 those who have come to regard Eozoon as a mineral structure. 

 With the presumption in its calcareous composition of an organic 

 origin, there has always existed a suspicion that some such expla- 

 nation as this might eventually be found. It is interesting to note 

 that the streakiness which Mr. Grreen expressly mentions as cha- 

 racterizing the interlamination of the olivine and coral sand rock, 

 is so frequently an accompaniment of " Eozonal " and serpentinous 

 limestone. 



