(4) Recent Æolian Sands.—On the south shore the sand has made or is making some encroachments on the land, in others on the sea. The ‘live’ sand-dunes are principally to be found at Tuckerstown, but there are some movements at Elbow (or Middleton) Bay and at Warwick Long Bay. The shell-sand is mostly made up of the broken shells of various marine species, some few being entire, with which are mingled the broken tubes of serpulæ, fragments of nullipores and corallines, and the red shells of a Vermetus, viz. Teganodus (Siliquaria) ruber, Schum. This latter is so plentiful as to give a distinctly red appearance to the sand of some beaches.