538 Transactions. 
so high up the rocks, are Cellana ornata (21 mm.) and C. strigilis (30 mm.). 
Both species have eroded apexes; and, as shown e measurements, 
only small specimens were found. Other molluscs observed in this 
association were Notoacmea pileopsis (small), Monodonta atrovirens, and 
M. coracina. 
Monodonta atrovirens, and Nerita melanotragus are found. 
Worser Bay, Wellington Harbour.—The only marine animals found 
above the wash of high tides are two species of Melaraphe—M. cincta and 
M. unifasciata. These occur on rocks, chiefly in crevices, up to 14 m. above 
high-tide mark. They are found above the lower limit of terrestrial vegeta- 
tion, often sheltering beneath the pendent branches of Mesembryanthemum 
australe. They seal themselves up behind their opercula and attach the 
outer edge of the peristome to the rock by a little mucilage. 
BURROWING-ANIMALS FORMATION. 
The species which are found associating together in this formation appear 
to be more dependent on habitat than in the previously described formations. 
The dominant form, a free pelecypod mollusc, is practically confined to а 
microlithic substratum, and hence characterizes the formation. Many of 
the other members—crabs, worms, brittle-stars, and gasteropods—seem 
equally fitted for a rocky coast with its variety of substations. The 
, 
obtain, well-marked associations are found. Coming into harbours, mud 
is the ruling factor; and with its greater stability comes a greater variety 
of life-forms—that is, mo , Worms, and gasteropods associated wit 
has a smooth, compressed shell; in mud, on the contrary, Antigona 
stutchburyi, the commonest species, the shell is sculptured and ventricose. 
Reference has also been made to the turreted form of gasteropod shell which 
is characteristic of microlithic substrata. In the intertidal belt in New 
Zealand Cerithidea bicarinata is the largest species with a shell of this form. 
e groups of associations in the two habitats, mud and sand, deserve 
the rank of subformations. The presence or abse ing-cr 
perhaps defines them. Besides the Amphidesma subtriangulata association, 
