Algal Communities, Stanmore Bay, N. Z. — Chapman 
67 
Lower Littoral Mixed Algal Formation 
4. Hormosira-Corallina association 
This association is extremely well-marked 
both on the flat rock shelf and also on the 
more varied rock faces of the bluffs. Hor 
mosira, Corallina officinalis, and C odium ad- 
haerens are present at all seasons, but Leathe- 
sia and Colpomenia are mainly to be found 
in the summer months. Corallina extends up 
beyond the normal limit of this association, 
but only where there are cracks or shallow- 
depressions that remain moist when the tide 
is below the upper limit of the association 
as a whole. 
Since this association is near low water 
mark, conditions are favourable for a num- 
ber of species and the flora is relatively rich. 
It also includes the serpulid V ermilia and 
FLermella spinulosa. The algal species are as 
follows: 
Leathesia difformis (spring and sum- 
mer) (ab.) 
Colpomenia sinuosa ( spring and sum- 
mer) (ab.) 
Microdictyon sp. (see footnote 2, p. 
65.) (o.) 
Laurencia thyrsifolia (f. ) 
Laurencia botryoclada (o. ) 
Laurencia pinnatifda ( o. ) 
Caulacanthus spinellus (l.f.) 
Jania sp. ( f . ) 
Rhizoclonium tortuosum (r.) 
Cystophora torulosa ( r. ) 
Dictyota dichotoma ( r. ) 
Dictyota ocellata (r.) 
Aphanocladia delicatula (1. ab.) 
Splachnidium rugosum (r.) 
Gigartina chapmanii (o.) 
Liagora harveyana ( f . ) 
( summer only ) 
Calothrix pilosa ( 1. ) 
ab. = abundant; f. = frequent; o. = occa- 
sional; r. = rare; 1. = locally. 
Suhlittoral Brown Kelp Formation 
5. Carpophyllum-Ecklonia association 
This was not studied in any detail but the 
upper limit of the association was established. 
The dominant species are Carp op by llum 
maschalocarpum, C. plumosum, and Ecklonia 
radiata. 
FRESHWATER SEEPAGE COMMUNITY 
There are one or two places where there 
is a steady trickle of fresh water over the sur- 
face of the rocks near high water mark. In 
such places a characteristic vegetation has 
developed dominated by Fntermorpha com- 
pressa f. subsimplex. A number of species 
are associated with the dominant and they 
include Rhizoclonium hieroglyphicum (f. ), 
R. riparium (f.) , Calothrix scopulorum, No- 
dularia harveyana, Microcoleus acutissimus, 
and Rivularia polyotis , 3 
TIDAL PHENOMENA 
A temporary tide pole was established at 
Stanmore and several successive readings of 
high tides were noted on this pole or on the 
adjacent vertical rocks. These marks were 
subsequently levelled with a theodolite and 
at the same time a series of positions marking 
the upper and lower limits of the major com- 
munities was levelled. The levelled readings 
of the high tides were then compared with 
the records from the tide machine in Auck- 
land Harbour, and, after allowance had been 
made for tides obviously affected by winds, 
it was found that 5.2 feet on the tide pole 
corresponded to 8.5 feet on the Auckland 
Harbour Board datum. 
ASSOCIATION LEVELS 
When the levels were examined it was 
found that in the case of the mussel and the 
Chamaesipho species the upper limits on the 
flat beach rock were lower than those on the 
vertical faces of the bluff rocks. This eleva- 
:! The author is grateful to Dr. F. Drouet for 
identification of some of the Myxophyceae. 
