These great photographs were taken around Jack's Point in the Catlins by Jan Williams and sent to us for identification. It is the Large Siphon Limpet (Siphonaria obliquita) with its egg mass.
It reaches lengths of 50 mm and the adult is visible in one of the photos below next to the egg mass. It is found around the South Island and southern North Island in the high and mid tide zone and hangs out in shady spots so may not be found next to its eggs. It is unusual as it has a primitive lung to aid survival when out of the water.
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