STRUTHIOLARIA VERMIS (Plate IV.).—Fig. 5 is smaller than the Struthiolaria papulosa, which it resembles in its habits of growth. It is a pale brownish or yellowish shell, usually without nodules; and on the edge of each whorl nearest to the spire is a groove, as shown in the plate. The best Struthiolaria papulosa are found in the clean sandy margins of tidal channels, but their burrowing habits make them difficult to detect. I have never found the Struthiolaria vermis except cast up on ocean beaches, and it is comparatively rare. The Struthiolaria family, which derives its name from Struthio, an ostrich, as its mouth is supposed to be shaped like an ostrich's foot, is found only in New Zealand, Australia, and Kerguelen's Land. The Maori name is Takai.
EUTHRIA LINEATA (Plate IV.).—Fig. 6 (late Pisania lineata) is a solid, heavy shell, varying from grey to brown, and the lines shown in the plate are almost black. It is sometimes one and a-half inches long, and is found under stones and rocks. The colours vary very much, and the lines, in number and breadth, vary even more.
EUTHRIA FLAVESCENS (Plate IV.).—Fig. 9 (late Pisania flavescens) is a whitish or orange variety, with very pale markings, and much smaller than the Euthria lineata.
EUTHRIA VITTATA (Plate IV.).—Fig. 10 (late Pisania vittata) is a yellowish-brown shell, with broad brown bands. Another variety of the Euthria is somewhat like the Cominella lurida (Plate IV., Fig. 7) in shape and size. Another, the Euthria littorinoides, is an orange-brown shell, but the interior of the aperture is a pale flesh-colour. In other respects, it is like the Euthria lineata. It is very difficult to draw any distinct line of demarcation between the varieties of this variable shell.
Figs. 7, 8, 11, 12, 13, and 14 are of the Cominella family, the New Zealand representatives of the voracious English whelks.
COMINELLA LURIDA (Plate IV.).—Fig. 7 is the most active and, for its size, the most voracious of our shellfish. Found in all harbours in the Province of Auckland, even up to high water mark, this greedy little animal, seldom more than an inch long, is well worth watching. In some localities, when a cart has been driven along a beach, the track, as soon as the tide reaches it, will swarm with the Cominella lurida. They are looking for cockles or other shellfish smashed by the wheel, and will even burrow in the sand to get at them. If you lift up a broken or injured cockle, some will cling to it with their rasp-like tongues till they are lifted out of the water. In calm, sunny weather, what looks like little bits of fat or candle-grease will be seen floating with the rising tide in very shallow water. These are Cominella lurida, which have perhaps eaten up everything in their vicinity, and have therefore decided to emigrate. A Cominella lurida, when shifting camp, will turn upside down, spread out its large white foot into a cup-shape, and let the rising tide sweep it along. They vary very much, from grey to purple or black, and sometimes even a mixture of two or more of these colours.
COMINELLA HUTTONI (Plate IV.).—Fig. 8 is a small pale brown shell, spotted with reddish-brown. The ridges on the exterior of the shell make it easy to identify.
COMINELLA MACULATA (Plate IV.).—Fig. 11 is a yellowish shell, with reddish-purple spots on the outside, the interior being also yellow. Its length is sometimes over two inches, and it is found in large numbers on sandy or shelly beaches, near low-water mark, in the North Island. Although a heavy, solid shell, it is of coarse texture, and therefore open to attacks by animal and vegetable parasites. A large specimen in good order is by no means common, the spire, or upper end of the shell, as shown in the plate, being usually worm-eaten.
COMINELLA TESTUDINEA (Plate IV.).—Fig. 12 is a handsome purple shell, the interior being darker than the exterior. It is about the same length as the Cominella maculata, but narrower, and the shell is thinner and harder. The exterior is covered with brown and white spots and splashes. It is common in the North Island and as far south as Banks' Peninsula. It is found on cockle banks and amongst rocks, especially those where sand is mixed with mud. The name Testudinea, from Latin testudo, a tortoise, is an appropriate one, as when held up to the light this Cominella looks like tortoise-shell.
COMINELLA VIRGATA (Plate IV.).—Fig. 13 is a greyish-brown shell, the raised lines, or ridges, that cross it being almost black. I have rarely found it, except amongst rocks in the harbours. It is much narrower than the Cominella testudinea, and not quite as long. The best way to obtain good specimens of these two Cominella is to break limpets, or other shellfish, and throw them into shallow water, close to rocks. In a few minutes, on revisiting the baits, the best specimens can be selected for the cabinet.