pollution. It is stated that during 1913 carcases of 33 dead horses were dumped between Tiri Tiri and Great Barrier Islands. Within three days many carcases had drifted right back on to beaches in the Auckland Harbour, including St. Heliers Bay. Earlier, in 1911, a damaged cargo of mutton was dumped near Great Barrier. It took only a few days for this to drift as far back as Motuihi and Browns Island. These facts are not conclusive in themselves without accompanying data on wind force and direction, as well as accurate tidal information. Nevertheless a north-easterly gale has been known to bring ashore at Glendowie (east of St. Heliers) specimens of Carpophyllum elongatum, which is confined in the Gulf to small islands west of Port Fitzroy and to the extreme north-east tip of Coromandel Penisula. ii. Tide Levels In any water mass partly enclosed by land considerable variations in both time and height of the tide may be expected to occur. Many workers on intertidal ecology have found from experience that, owing to a frequent deviation of tidal behaviour from the normal for the nearest port of reference, each locality needs to be studied on its own. In the Hauraki Gulf extreme spring tides range from about 14. Oft. in Coromandel Harbour to about 8 Oft. at Cuvier Island. Taking Auckland as the standard port of reference, the following figures taken from the Nautical Almanac (1950) give the ratio of the tide ranges for localities where it is known: Auckland 1.00 Coromandel 1.19 Tryphena 0.74 Cuvier Island 0.70 Mercury Bay 0.64 The writer's brief observations of tidal behaviour in the Gulf (Table V) varied from that made over a weekly period (Station 24) to those over a single 6-hourly rise or fall of the tide (Stations 17, 30, 32). Table V. Tidal Observations in the Hauiaki Gulf. Station Tide Range in Feet No. Location Date −Splash +Splash Predicted Spring or Neap 17 1.9.50 8.1 8.4 7.9 (Auckland) Spring 24 Ti Titoki Flat 17.10.49 4.7 5.0 4.0 (Tryphena) Neap 24 Ti Titoki Flat 24.10.49 6.5 8.0 8.0 (Tryphena) Spring 27 Long Beach 18.5.49 6.3 6.3 9.1 (Coromandel) Neap 28 Fletchers Bay 17.5.50 4.0 5.2 5.1 (Cuvier Is.) Neap 30 Whitianga 15.5.49 6.6 7.0 6.8 (Mercury Bay) Spring 32 Port Fitzroy 6.4.50 7.3 7.5 8.1 (Tryphena) Spring In the above table the Coromandel Harbour figures are obviously not applicable to Long Beach, which is only 5 miles away, but is situated on the open coast. Results from Ti Titoki Flat, Little Barrier, also appear anomalous in comparison with the expected ranges at Tryphena. The neap range is greater but the spring range is smaller, if splash is not taken into account. The splash zone (Colman, 1933) was particularly hard to estimate here owing to the broken surface topography occasioned by the loose stones and boulders. Figures from Fletchers Bay agree substantially with the expected record for Cuvier Island; likewise Whitianga with Mercury Bay. and Arran with Auckland. The range at Port Fitzroy appears on superficial examination to be slightly less than at Tryphena,