OLIVER.— Marine Littoral Plant and Animal Communities. 543 
Among Zostera in shallow pools ате shrimps, small crabs, and Haminea 
zealandica. Also, attached to Zostera leaves and other objects, are two 
species of a sea-anemone and a small button-like alga. Common in these 
shallow pools are little clumps of Corallina officinalis entangled with a 
sponge, on which are found numbers of Cerithidea subcarinata, Dardanula 
olivacea, turbellarians, and small crabs 
Notoacmea scapha I have found in other parts of Tauranga Harbour not 
far from Sulphur Point. It was observed only on the leaves of Zostera. 
The shell is narrow, not wider than the leaf, and about twice as long as 
broad. It thus differs in shape from all the other New Zealand species of 
Acmeidae, and the peculiar outline is evidently related to its station. By 
not projecting beyond the margin of the Zostera leaf it offers the minimum 
amount of resistance to the action of tide and waves. 
Parenga Harbour.—On mud-flats between tides in the most northern 
harbour in New Zealand are extensive areas covered with Zostera mana. 
slightly discoloured, low sculpture, and rounded not ventricose valves ; 
Paphia intermedia, 43 mm. ; Amphidesma novae-zealandiae, 50 mm., with 
dark-coloured periostracum; and Tellina liliana. On the surface there 
occur Alcithoe arabica elongata, with shells that show a good deal of 
erosion but are not discoloured, and show also the colour-pattern on 
the body-whorl On Zostera leaves are Trophon ambiguus, Mono 
atrovirens, and Cantharidus tenebrosus huttoni. 
eature of the Zostera beds are loose stones lying about. They support 
Elminius modestus, Mytilus planulatus, aethiops, Siphonaria zea- 
landica, Hormosira Banksii, and other small algae. Оп the under-side are 
Euthria linea, E. flavescens, Neothais lacunosa squamatus, Amaurochiton 
laucus, Ischnochiton campbelli, and various worms. These rock-associations 
are evidently but detached portions of a shelled-animals formation of 
the adjacent rocky coast. 
SALT-REED-SWAMP FORMATION. 
In harbours in New Zealand the outer fringe of salt reed swamps 
is аас ip tidal waters. In such places part of the marine fauna of the 
cos srl pore Me the landward border of tidal mud-flats 
which the species occupyi 
lex 
ш % j ] а on the 
d here b the mud is the crab Helice crassa, an ) 
ert he ма оа Amphibola crenata. Farther inland other species 
of plants enter, and there are often mud lanes lined with Samolus repens 
