24 
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 1} inches across. 
CALLICSTOMA PUNCTULATUM (Plate VI.).—Fig. 4 
(late Zizyphinus punctulatus) is the commonest and least fragile 
of this family. It is seldom more than 1} 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. 
