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Dwellers of the Sea and Shore 



and are the products of very ancient animals called 

 nummulites. Nummulites were protozoans, and they 

 lived in the sea ; the shells they secreted were coinlike 

 in shape (hence the name). Internally these have a 

 spiral cavity divided by partitions into numerous cham- 

 bers. They seem to have no external opening, but the 

 chambers communicate with each other by small per- 

 forations. Now the nummulites became extinct a long 

 time ago; so long ago, in fact, that the earth has since 



NUMMULITES. 



been populated with other creatures, many of whom In 

 their turn have died out too. So it will be seen that 

 ages before the pyramids were built, perhaps before 

 there was dry land where they now stand, these minute 

 creatures were at work making the material out of 

 which those structures were finally formed. 



It is by the fossils we find In the rocks, of course, that 

 we know what lived in the ancient seas. We also have 

 means of knowing what rocks are oldest; therefore, we 

 are guided by the creatures they contain in forming an 



