VOL. XLIX.] PHILOSOPHICAL TRANSACTIONS. 705 



particular species are found ; and lastly, there are other places, in which neither 

 plants nor animals are to be met with. These observations not only point out 

 the affinity and resemblance between the surface of the earth and the bottom of 

 the sea ; but may likewise contribute to discover one cause of the varieties which 

 are observed in the distribution of the marine fossils found in the earth. Dr. 

 Donati remarked in that vast mass of marble, which is common to the bottom of 

 one part of the Adriatic sea, and to the neighbouring provinces towards the 

 east, a multitude of marine bodies petrified ; some of which are so united to the 

 stony substance, that they are scarcely to be distinguished. He found in some 

 places human bones petrified, which form one mass with a mixture of marble, 

 red earth, and stalactites. 



One of the objects, which most excited the attention of our author, was a 

 crust, which he discovered under the water in divers places, and for a great ex- 

 tent. It is a composition of crustaceous and testaceous bodies and beds of polypes 

 of different kinds, confusedly blended with earth, sand, and gravel. They are 

 found at the depth of a foot or more, entirely petrified and reduced to marble. 

 At less than a foot deep they approach nearer to their natural state. And at the 

 surface of this crust, they are either dead, though extremely well preserved, or 

 still living. This observation demonstrates, that stones or petrifactions may be 

 formed, and actually are formed, in great quantities under the water. 



It is to be remarked, that these crustaceous and testaceous bodies and beds of 

 polypes, are every where mingled in the utmost confusion with each other : 

 which shows a striking resemblance between the crust discovered at the bottom 

 of the sea, and those of the marine bodies petrified, found in many parts under 

 the earth, and especially in Italy. If these marine bodies petrified are naturally 

 in that confusion in the sea ; if they were born and die ; and if they have been 

 petrified in that state ; it is highly probable, that those which are found under- 

 ground in the strata in such confusion, are likewise placed naturally in the same 

 manner under the sea, when it covers them, and not by means of extraordinary 

 events, such as volcanos and earthquakes, as has been conjectured. 



The more these bodies and beds of polypes multiply, the more their exuviae 

 and skeletons contribute to enlarge this crust discovered at the bottom of the sea. 

 Dr. Donati remarked, that in several parts it formed very considerable banks, 

 and of a very great thickness. Hence it follows that the bottom of the sea is 

 constantly rising higher and higher. Divers other causes contribute to it. Snow 

 and rain-waters bring down from the neighbouring mountains, into the sea, a 

 great quantity of earth and stones. The waves, beating against the shores of 

 the continent and islands, detach many masses, which are spread upon the bot- 

 tom of the sea. The rivers carry the mud with their waters into the sea, at the 

 bottom of which that mud deposits itself. From the rising of the bottom of the 



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