74 The Vegetation of the Sea-coast. 
with a thin layer of blackish soil, bearing a close covering of grass or heath. 
Swamps and shallow sheets of water are common features in extensive dune areas. 
The dune-landscape does not everywhere present the features described 
above. Generally, there is no regularly shaped foredune. The wandering dune 
may not be confined to the landward boundary, but the hills of the dune- 
complex, advancing one upon another, will have formed, or be»still forming 
wandering-dune. Hollows may be either slowly extending as a hill recedes, 
or in process of extinction as hills advance, or a stream of sand pours through 
some opening. 
dune-area may be ed to a few hillocks or a slight ridge on the 
upper shore. On the other hand, there may be a series of miniature moun- 
tains more than 60 m high “ir deep valleys between. In some parts of 
 Taranaki and Auckland, cliffs, themselves often consolidated dunes, face the 
ocean, while at high-water there is no exposed beach at their base. Such 
are capped br enormous GEDORE. of sand which are not infrequentiy advan- 
i  eing inland. 
"The ecological Koirhone governing dune-vegetätion are der severe 
"and for the most part are strongly xerophytic in character. But the special 
feature is the Arne: sand cal ‚only be withstood by plants posses- 
sing special sand-binding ” in no small degree. On some ‚parts of 
* 
s the coast, ee Ex at times, the effect of which is felt for many kilo- x 
