34 [March, 1846. 



" I saw in the proceedings of your Society a notice of Dr. Tay- 

 lor's specimens, describing them as from the carboniferous lime- 

 done. Mr. Featherstonhaugh and Dr. Troost have given authori- 

 ty, I believe, for calling this limestone the carboniferous, and in 

 a paper read before our geological Association, I maintained the 

 same views chiefly from Lithological characters. The more ac- 

 curate test by the fossil remains, I am convinced determines our 

 limestone to be the equivalent of the Lower Silurian. With this 

 view it is interesting to find the Asterias at so low a point in the 

 geological column ; as it was formerly supposed not to extend 

 below even the secondary rocks." 



The Committee on Mr. Edward Harris's paper on the dif- 

 ference of level between the waters of the Gulf of Mexico 

 and those of the Atlantic Ocean, reported in favor of pub- 

 lication. 



On the Difference of Level between the Waters of the Gulf of 

 Mexico and those of the Atlantic Ocean. 



By Edward Harris. 



While on a passage along the coast of Florida in the spring of 

 1844, in the U. S. Revenue Cutter Nautilus, Capt. Waldron, 

 having on board Mr. Stacy, U. States Commissioner for the in- 

 spection of the Lighthouses, we stopped on the 28th of April to 

 examine at Key Biscayne, the ruins of the lighthouse burnt by 

 the Indians in 1836. The next day we took the boats with kegs 

 to procure water for the vessel ; passed inside of Cape Florida, 

 and ascended the Miami River about five miles to where it issues 

 from the Everglades. I was surprised to find that the water 

 from the everglades falls into the river over an exceedingly 

 porous limestone rock resembling Travertine, so open, that in nu- 

 merous places at the foot of the rapids, which are about two 

 hundred yards in length, the water spouts up from the small 

 round holes in the rock, in little natural fountains of from one foot 

 to eighteen inches in height. I estimated the fall at from seven 

 to eight feet, which cannot be far from the truth, as there is a mill 

 at their foot for grinding the Coontic root, {Zamia integrifolia , 



