The walls, both internally and externally, are encrusted with marbles.
Many Siphonales are encrusted of planes and a multicellular individual.
But in other cases the encrusted star settles in that portion of the revolving vortex which has a velocity equivalent to its own, and so continues to revolve in the vortex, wrapped in its own firmament.
Some species belonging to the families Squamariaceae and Corallinaceae grow attached through their whole length and breadth, and are often encrusted with lime.
Some of the boulders are encrusted by marine organisms and must have been dropped by icebergs in the sea.