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water tank at the entrance to Tauranga Harbour, but never found them except in spring or early summer. The Maori name is Mata-ngo-ngore, which name is also used for the Cantharidus family, on Plate VII.
CALLIOSTOMA SELECTUM (Plate VI.).—Fig. 2 (late Zizyphinus cunninghamii) is about the same width, but not the same height as the Tigris. The colour is white, with pale red spots arranged in rows around the spire.
CALLIOSTOMA PELLUCIDUM (Plate VI.).—Fig. 3 (late Zizyphinus selectus) is a whitish shell, covered with chestnut-coloured spots and splashes. It is about 1½ inches across.
CALLIOSTOMA PUNCTULATUM (Plate VI.).—Fig. 4 (late Zizyphinus punctulatus) is the commonest and least fragile of this family. It is seldom more than 1¼ inches across. Its rounded whorls, and prominent chestnut and white granules, make it easily distinguishable.
TROCHUS VIRIDIS (Plate VI.).—Fig. 5 is a greenish, cone-shaped shell. The interior is nacreous, and the exterior covered with coarse granules. The base, which is flat, is greyish. The figure but faintly shows the contour of this shell, which is a perfect cone, The young differ somewhat from the adult shells, and have a bright pink tip to the spire. In the plate the upper shell is a young one, and the two lower are adults. They are found amongst rocks at low water mark, in harbours, as well as in the surf. It is very difficult to extract the animal from the shell. Its maximum size is one inch across.
TROCHUS TIARATUS (Plate VI.).—Fig. 6 is usually white, with large grey or brownish-purple dots and bands on both the upper surface and the base, but it is a very variable shell. It is seldom as much as half an inch in length, and has a nacreous interior. It is covered with fine granules, and the base is flat. It appears to live slightly below low water mark, and can be easily obtained by dredging in harbours. The cup-shaped hollow at the base of the spire is much more pronounced than in the Viridis.
There is another not shown on the plate, the Thochus chathamensis, a small white shell, with pink or brownish-purple markings, that hitherto has only been found in the Chatham Islands.
