ng
form of the ordinary variety. The Maori name is Ata marama.

~ASTRALIUM SULCATUM~ (Plate VI.).--Fig. 18 (late Cookia sulcata) is a
pinkish-brown shell, sometimes over 3-1/2 inches wide. The interior is
pearly, and the operculum is shelly, solid, and white. The laminae which
cover the shell are easily bleached off, and when the shell is cleaned
it has a handsome appearance. It is found in considerable numbers at low
water mark amongst rocks on exposed beaches all over the North Island.
The Maori name is Kakara or Kaeo, both of which names are also given to
the Purpura haustrum (Plate II., Fig. 11).

~ASTRALIUM HELIOTROPIUM~ (Plate VI.).--Fig. 19 is generally known as the
circular-saw shell, and, although found all over New Zealand, is
comparatively rare. It is reddish-purple, with an iridescent interior,
and is sometimes over four inches in width. The shells on the plate are
adults. The spines of the younger shells are much longer than those of
adults. The best specimens have been dredged by oyster boats.

Plate VII.--Figs. 1 and 2 are Janthina, or violet shells,
representatives of which are found all over the warmer parts of the
world. The Janthinae live in great numbers on the surface of the ocean,
being unable to sink, and are swept by gales and currents in every
direction. At intervals, after very heavy gales, they come ashore in the
Northern part of New Zealand in cart-loads; but after any ordinary gale
a few specimens can be procured amongst the grass cast up by the highest
waves. The animal, when touched, emits a quantity of violet-coloured
fluid, the same colour as the shell. The shells are very light and
fragile. A singular provision for its eggs is found attached to the
female Janthina, in the shape of a float, or raft, to the under surface
of which the eggs in little bags or capsules are attached, and there
they remain until hatched.

~JANTHINA EXIGUA~ (Plate VII.).--Fig. 1 is the smallest of the Janthina
found in New Zealand, being rarely half an inch in width. The whorls are
more rounded than in the other two varieties, and the spire is usually
the same violet colour as the mouth, and the grooves on the shell are
deep and prominent.

~JANTHINA FRAGILIS~ (Plate VII.).--Fig. 2 is sometimes over an inch in
width, the spire being much lighter in colour than the rest of the
shell, frequently indeed being white. The grooves on the shell are fine,
but clearly visible.

There is another variety occasionall