These notes concern two of New Zealand's off-shore islands, Stewart Island, in the south, comes within the Forsterian marine province, but Great Barrier Island, which lies some 50 miles from Auckland, is within the Aupourian/cookian zone which is affected by the warm current from East Australia.
Common to both islands are 3 species of Haliotis, (H. iris, H. australis and H. virginea), but the bigger and heavier specimens of the first-named are those prised from rocky ledges - often under dangerous con¬ditions of rough seas - by the Stewart Island fishermen. These shells are used in workshops organised by the Returned Servicemen's Association, where they are made up into dress jewellery and other ornamental objects, and con¬sequently their export from New Zealand is normally prohibited.
Among the less common shells, Astraea heliotropium, although mainly a deep water shell, can be found occasionally cast up and wedged among the rocks on Stewart Island. On the sandy beaches Struthiolaria papulosa gigas and Alcithoe swainsoni (the latter mentioned by A. W. B. Powell as being more common in the south) are both to be found in fair quantity and although not live, in good condition.
The Stewart Island oyster (Ostrea sinuata) must be dredged. The rock oyster of the Auckland region (Saxostrea glomerata) is more accessible, though any temptation to sample those almost on our doorstep on Great Barrier Island had to be resisted, as unauthorised gathering is forbidden. The eastern coastline of that island with its many wide sandy stretches contrasts strongly with the deep-water rocky bays of the western shore. Along the sandy shores a highly coloured line of Chlamys valves often edges high tide mark, and once, after a storm, we found a wide semicircle of Janthina, but we never found the one shell for which we greatly hoped - the Argonaut.
With the occurrence in this northerly zone of warmer water molluscan genera, one may expect to find representatives such as Tonna liaurakiensis and Xenophalium pyrum, but to find a good specimen of Xenophora neoselica, as well as Xenophalium labiatum and an (incomplete) Bullinula lineata did much to compensate for other blank collecting days.
On certain smooth rocks in the western bays of the island it is possible to find Acmaea fragilis, though they are difficult to remove without damage to the edges. A shell which seems to occur only in the northern marine provinces is Maurea tigris, one of the more handsome representatives of the Calliostomatidae. Among the smaller species of Trochidae, Cantharidella tesselata of fair size can be found grouped here and there on the rocks of Great Barrier Island.
Miss L. F. Hanna