71 
In conclusion, the object of this paper is to draw attention 
to the great masses of these bodies and the importance of 
always noticing their occurrence in geological formations, 
since it should be a very material help in regard to the cli- 
mate, and the conditions of the coasts and currents, besides 
being of great stratigraphical assistance; nor is it of less 
importance to note carefully the growth of recent ones, for 
only through a knowledge of the present can we interpret 
the past. 
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