wn in the plate. The interior is white, and the
shell is found up to three inches in length.

~VOLSELLA AUSTRALIS~ (Plate X.).--Fig. 7 (late Modiola australis) is a
rough-looking, uneven shell, of a pale chestnut colour. It usually has a
hairy-looking growth near the edge, as shown in the plate. It is found
up to four inches in length.

There are two other of the Volsella family in New Zealand, neither of
which are illustrated. The Volsella fluviatilis, a shiny, black mussel,
shaped like the Edulis, and about 1-1/2 inches long, found in brackish
water, is the most common. The inside is bluish-white, and purplish
round the margin.

~OSTREA ANGASI~ (Plate X.).--Fig. 8 is a mud oyster, of which those
dredged at Stewart's Island are the largest we have. Fine specimens were
found in Ohiwa Harbour prior to the Tarawera eruption of 1886, but the
deposit from that eruption appears for the time being to have destroyed
them. There must be some large banks of this oyster in the Bay of
Plenty, judging by the number of dead shells washed up in places; but,
although I many times used the dredge while in Tauranga, I never had the
good fortune to find one of the banks. Cartloads of the shells were at
times washed up on the beach between the town of Tauranga and the
entrance to the harbour.

The best known oyster in New Zealand is the Auckland rock oyster, the
Ostrea glomerata (not shown in the plate), which is familiar to all who
visit the seashore in the North. The Maori name for the rock oyster is
Tio, and for the mud oyster Tiopara.

~PLACUNANOMIA ZELANDICA~ (Plate X.).--Fig. 9 is of the family known in
England as the pepper and salt oyster. The lower valve is flat and has
the large oval opening, shown in the plate, through which the foot of
the animal protrudes and holds the shell on to the rock. The shell is
thin and fragile, and is found in both Islands. Another shell of the
same family, the Anomia walteri (not shown on plate), is found at the
Bay of Islands, and is usually coloured bright yellow or orange.

~MUREX RAMOSUS~, the last figure, is the latest addition to our New
Zealand marine shells, and is described with the others of the Murex
family on Plate II., and on page 16.

[Illustration: PLATE I.

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Argonauta nodosa 14
Spirula peroni 15]

[Illustration: PLATE II.

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1--Murex zelandicus 15
2--Murex octogon