Among Zostera in shallow pools are 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 nana. Beneath the surface are many crabs of the species Hemiplax hiritpes; also the pelecypods Antigona stutcliburyi, 20 mm. and under in length, and Nucula hartvigiana. On the surface the following gasteropods are found: Lepsiella scobina, large shells up to 35 mm. in length and with the entire outer surface eroded, and often supporting Vermilia carinifera; Turbo smaragdus, fairly clean shells with eroded apex and carrying Crepidula crepidula and Vermilia carinifera; Cominella lurida, with outer surface entirely eroded; Monodonta subrostrata: Cerithidea bicarinata and C. subcarinata. The chiton Acanthochiton zealandicus also occurs in this association. Golden Bay, Stewart Island.—Between tide-marks are areas of sandy flats covered with Zostera. Compared with other parts of New Zealand this is a fairly rich association, with large molluscs. Burrowing beneath the surface are Hemiplax hirtipes; Antigona stutchburyi, up to 46 mm. in length, slightly discoloured, low sculpture, and rounded not ventricose valves; Paphia intermedia, 43 mm.; Amphidesma novae-zealandiae, 50 mm., with dark-coloured periostracurn; 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 anibiguus, Monodonta atrovirens, and Gantharidus tenebrosus huttoni. A feature of the Zostera beds are loose stones lying about. They support Elminius modestus, Mytilus planulatus, Monodonta aethiops, Siphonaria zealandica, Hormosira Banksii, and other small algae. On the under-side are Euthria linea, E. flavescens, Neothais lacunpsa squamatus, Amaurochiton glaziczis, Ischnochiton camphelli, 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 many harbours in New Zealand the outer fringe of salt reed swamps is invaded by tidal waters. In such places part of the marine fauna of the adjacent mud-flats is found. Tauranga Harbour.—Along the landward border of tidal mud-flats considerable stretches of the shore are occupied by salt reed swamp, of which the species occupying the outside edge are Juncus maritimus and Leplocarpus simplex. High tide floods a strip of varying width, and here burrowing in the mud is the crab Helice crassa, and on the surface the gasteropod Amphibola crenata. Farther inland other species of plants enter, and there are often mud lanes lined with Samolus repens