The substitution of steamships for sailing vessels has brought about a diminution in the number of vessels belonging to the Italian mercantile marine, whether employed in the coasting trade, the fisheries or in traffic on the high seas.
The marine facies of the later Tertiaries is confined to the neighbourhood of the coast, and was probably formed after the elevation of the Andes; but inland, freshwater deposits of this period are met with, especially in Patagonia.
Portions most liable to destruction, those parts between the tide marks, were found perfectly sound, and showed no signs of the ravages of marine organisms. Other valuable timber trees of the eastern portion of the continent are the blackbutt, tallow-wood, spotted gum, red gum, mahogany, and blue gum, eucalyptus; and the turpentine (Syncarpialaurifolia), which has proved to be more resistant to the attacks of teredo than any other timber and is largely used in wharf construction in infested waters.
Tetraplatia volitans Viguier is a remarkable floating marine form.