66 
PACIFIC SCIENCE, Vol. IV, January, 1950 
Apophloea sinclairii, is normally co-dominant. 
The red alga is to be found in this belt at 
Stanmore, but not in abundance. In order 
areas also there is usually some development 
of Chamaesipho brunnea but the species is 
not common in this locality. The species of 
Chamaesipho extend rather higher than does 
the Volsella. The associated species vary with 
the physiography but among the mollusks 
one may find both species of limpet, Cellana 
ornata and C. radians. On the flat beach rock 
one finds black patches of Isactis plana, Sym- 
ploca laeteviridis, Microcoleus tenerrimus, 
Calothrix scopulorum, and red patches of 
what appears to be Hildenbrandtia sp. Coral- 
lina occurs in shallow pools, though if the 
pools are sandy it is replaced by Pylaiella 
(Bachelotia) novae-zelandiae (Chapman and 
Ambler, in press). In places the Isactis and 
Symploca are sufficiently abundant to form 
a distinct fasciation: the former does not 
extend to quite the same height as the Vol- 
sella. Symploca tends to replace the other 
alga in this area. 
At the bluffs, where there are vertical rock 
faces, other species are to be found. These 
include a more frequent appearance of the 
large barnacle Elminius plicatus, the limpets 
Cellana ornata and C. radians, and the fol- 
lowing algae: Caulacanthus spinellus, Geli- 
dium pus ilium G. caulacantheum, Bostrychia 
arbuscula, Rhizoclonium hookeri, and Poly- 
sip honia rudis. It is here also that occasional 
patches of Apophloea may be seen. 
The Caulacanthus is interesting because 
each colony appears to have started within 
a group of mussels and to have radiated oui 
from that centre, so that each group of mus- 
sels becomes surrounded by a ring of the 
algal felt. 
3. Vermilia-Saxostrea association 
Both the species (V ermilia carinifera and 
Saxostrea glomerata) occupy a well-marked 
zone. The rock oyster is rather more abun- 
dant than the serpulid worm and also extends 
to a higher level on the shore, so that it over - 
laps into the association described above. 
Likewise the V ermilia often descends some- 
what lower on the shore than the oyster. An 
alternative treatment would be to separate 
these animals into two independent commu- 
nities but in view of the overlap they are here 
retained as one association. This community 
is absent from the flat shelf and is only to be 
found on the more resistant rocks of the 
Fig. 3. The flat shelving beach at Stanmore Bay. 
bluffs. The associated species are not numer- 
ous and include Chamaesipho columna, El- 
minius plicatus, Caulacanthus spinellus, Geli- 
dium pusillum, Peyssonelia sp., Corallina of 
fcinalis (basal portion only), and Lyngbya 
confervoides. 
At the bluff the lower part of this zone 
is further characterised by a considerable local 
development of Ralfsia verrucosa and also of 
the worm Hermella spinulosa. Scattered 
through both the Chamaesipho— Volsella and 
V ermilia— Saxostrea associations one may find 
the mollusks Lunella smaragda and Lepsiella 
scobina. 
