Inter-tidal Ecology at Narrow Neck Reef — Dellow 
359 
Mean High Water Springs 
(M.H.W.S. ) . 11.41 
Mean High Water Mark 
(M.H.W.M. ) 10.35 
Mean High Water Neaps 
(M.H.W.N. ) ............ 9.28 
Extreme (Lowest) High Water 
Neaps (E.(L).H.W.N.) 8.88 
Mean Sea Level (M.S.L.) 6.22 
Extreme (Highest) Low Water 
Neaps (E. (H) .L.W.N.) 3.96 
Mean Low Water Neaps 
(M.L.W.N.) . 3.29 
Mean Low Water Mark 
(M.L.W.M. ) . 2.29 
Mean Low Water Springs 
(M.L.W.S.) ............ 1.12 
Extreme Low Water Springs 
(E.L.W.S. ) 0.60 
Auckland Harbour Board Datum 
( A.H.B.D.) 0.00 
LEVELING SURVEY 
To obtain quantitative data concerning the 
levels and vertical range of the more impor- 
tant littoral plants and animals, a series of 
traverses was made in different parts of the 
area (see Figs. 1 and 3-6). In each case, the 
leveling staff was placed as near as possible 
to the average limit of the vertical range of 
the species. Elevation or depression levels 
due to local modifications were not taken into 
account. Levels of species such as Caulerpa 
sedoides and Splachnidium rugosum which 
did not occur across the paths of the traverses 
were obtained as isolated spot-heights from 
elsewhere within the area. The traverses were 
90 
100 
E.H.WS. 
M.RWS. 
KHW.M. 
KHW.M. 
ELH.WN. 
MS.L. 
E.HLWN. 
M.LW.N. 
MLVm 
M.LW.S. 
EL.W.S. 
AJiB.D. 
r*ET 
■1 1.95 
■11 41 
•10.35 
>9.28 
+ 6.22 
+ 3.96 
+i3.29 
+2.29 
+ 1.12 
+0.60 
0.00 
TRAVERSE A — ACROSS HEADLAND 
Vertical Scale * Twice Horizontal 
CALOTHRIX SCOPULORUM 
^ RHIZ0CL0NIUM RIPAR1UM 
S BANCIA VERMICULARIS 
ENTEROMORPHA ACANTHOPHORA* 
mm CHAMAESIPHO COLUMNA 
mm ELMINIUS PLICATUS 
EE3 SAXOSTREA GLOME RATA 
E23 VERMIUA CARINIFERA 
EH3 hermella SPINULOSA 
EH GELID1UM PUSILLUM 
EZZ1 VOLSELLA NEOZELANICUS 
Fig. 3. Traverse A. (* Found to be Enterom,orpha procera f. minuta. ) 
