MUREX ZELANDICUS (Plate II.).—Fig. 1 is known as the spider shell, from the spines, which look like spider's legs. It is a white or greyish shell, about two inches in length. The long spines would interfere with the growth of this Murex if it had not the power of dissolving them as the outside of one whorl becomes the inside of the next. The removal is supposed to be assisted by chemical action, as the saliva of some shellfish is known to contain a small percentage of muriatic acid. Such powers have some shellfish of dissolving or altering the form of their shells, that the Cyprae, or Cowry, our representative of which family is the Trivia australis (Plate VII., Fig. 29), not only can dissolve the inner part of its shell, but can deposit new layers on the outside. This Murex lives on sand in the open ocean, and is found in the North Island only.
MUREX OCTOGONUS (Plate II.).—Fig 2 is a slightly longer shell than the Murex zelandicus, and, like it, is found only in the North Island. But in place of being round or oval, this shell is octagonal, from which peculiarity it derives its name. The grooves that cross the shell are deep, and between them are small curved spines. The shell is thick and solid, the exterior being reddish white, sometimes stained with brown. There is a smaller variety of this shell, darker in colour and with more numerous spines than the photographed specimens shown.
MUREX EOS (Plate II.).—Fig. 3 is a beautiful pink shell, about an inch long. Dead shells only have been found, and a good specimen is much prized. None of the Murex family are common, and they are seldom found alive. Murex eos, although existing in Tasmania and Australia, has so far been found in New Zealand nowhere South of the Bay of Islands.
MUREX RAMOSUS.—Two specimens of this well-known Island shell have been found in Tauranga during the last five years. One excellent specimen, 8-1/2 inches long, was a live shell, and is now in the possession of Mrs. T. M. Humphreys, of Tauranga. An illustration of this shell will be found on Plate X., Fig. 10.
TROPHON STANGERI (Plate II.).—Fig. 4 is a rough grey shell, with a dark purple interior. It is covered with parallel ridges and lines, which are known as varices, very thin and close together, and running from the apex to the mouth of the shell. It is over an inch in length, and usually found on cockle banks in harbours.
TROPHON AMBIGUUS (Plate II.).—Fig. 5 is in shape very like the Murex stangeri, but twice the dimensions, and can be easily distinguished, as the varices are much higher and further apart; besides which they cross one another at right angles, forming a perfect network, and the interior is pinkish brown. This shell is found on ocean beaches, as well as on cockle banks.
TROPHON CHEESEMANI (Plate II.).—Fig. 6 is a small, grey Trophon, with a dark interior. The shell is deeply grooved, and about three-quarters of an inch long. Found, so far, only on the West Coast, near Waikato Heads. We have 3 other small Trophons, two of which are shown on Plate VII., Figs. 22 and 23.
ANCILLA AUSTRALIS (Plate II.)—Fig. 7 (also known as the New Zealand Olive) is a beautiful clean bright shell, and looks as if covered with shining enamel. The upper part of shells of the Ancilla family is kept polished by the mollusc's foot, which swells to such an extent when the animal is moving about that the whole shell is concealed in its folds. The broad band in the centre is usually dark chestnut or brownish purple, the points of the shell being tipped with darker shades of the same colour. The interior is purplish. Large numbers are found on the edges of channels in harbours, buried in the sand; but their presence is easily located by the oval-shaped mound under which they conceal themselves. When washed up on ocean beaches, they are frequently bleached to a brown or chocolate colour. The Maoris sometimes use them for buttons, and very pretty buttons the medium-sized ones make. The largest I have seen were two inches long. There are two other kinds of Ancilla found in New Zealand, the one much larger, and the other much smaller, than the one depicted. The larger is Ancilla pyramidalis, the smaller Ancilla mucronata. The native names are Pupurore and Tikoaka.
PURPURA SUCCINCTA (Plate II.).—Figs. 8 and 9 is found all over the North Island, on ocean beaches and in harbours. It may have a comparatively smooth exterior, as in Fig. 8, or be deeply grooved, as in Fig. 9. The interior is usually yellow or brown, and generally has a pale band round the margin of the outer lip. It is very variable in colour and general outside appearance, and although at one time divided by naturalists into 3 or 4 varieties, under different names, it is now believed to be only one very variable species.
PURPURA SCOBINA (Plate II.)—Fig. 10 (late Polytropa scobina) is a rough, thick, brown shell, with a dark interior. It varies in colour and shape, and is found everywhere in New Zealand on surf-beaten rocks. It is usually under an inch in length.