EMARGINULA STRIATULA (Plate IX.).—Fig. 26 is a whitish limpet, about an inch in length. The notch, or fissure, which is a peculiar feature of this shell, is seen on the end of the shell facing the Lima zelandica (Fig. 21).
CREPIDULA UNGUIFORMIS (Plate IX.).—Fig. 27 is a parasite shell, over an inch long, and found inside the lips of other shells. It is a thin, clear white shell, and is well named, from unguis, a finger-nail, which it much resembles. It varies in shape from nearly flat to semi-circular, according to the curve of the part of the shell on which it grows. The Crepidula shells are easily identified by the shelly internal appendage, or lamina, in which the body of the animal rests. From the peculiar effect of this lamina the Crepidula shell looks like a boat. This shell has recently been renamed Crepidula crepidula, a silly duplication, like Lima lima (Fig. 21). The Maori name for the Crepidula is the same as for a limpet, namely, Ngakahi or Ngakihi.
CREPIDULA ACULEATA (Plate IX.).—Fig. 28 (late Crepidula costata) is an oval-shaped white parasite shell, with purplish lines on the edge. It is a common shell in the North Island, and found on rocks and amongst roots of kelp, and on the outside of other shells, especially mussels. It varies in colour and shape, but is usually deeply ribbed, and attains a length of 1-1/2 inches.
There is another species of the Crepidula, viz., Monoxyla, similar in shape to the Crepidula aculeata, but white and smooth, and much smaller.
CALYPTRÆA MACULATA (Plate IX.).—Fig. 29 (late Galerus zelandicus) is a circular shell, found on rocks or kelp, and sometimes is attached to other shells, especially mussels. It attains a width of 1-1/2 inches, and is covered with a brown, hairy epidermis.
HIPPONYX AUSTRALIS (Plate IX.).—Fig. 30 is a limpet, which takes its name from its shape, being like a horse's foot. There was a colony of some hundreds of this Hipponyx under a flat rock, resting on other rocks, on the ocean side of Mount Maunganui, at the entrance to Tauranga Harbour. Although there were thousands of other rocks round it, I never found the Hipponyx except under the one rock I have mentioned, and as far as I know it has never been found alive in any other part of New Zealand.
DENTALIUM NANUM (Plate IX.).—Fig. 31 is like a miniature white tusk of an elephant. It is about 1-1/2 inches long. It is really a limpet, which, having chosen mud and sand as its habitat, has adapted itself to its surroundings and become long and thin, instead of broad and flat, like the rock-loving limpet. It is found on the West Coast of Auckland Province, especially between Manukau and Raglan.
ACMÆA OCTORADIATA (Plate IX.).—Fig. 32 is one of the dozen Acmæa found in New Zealand. It is a very flat shell, and lives amongst rocks in the surf.
ACMÆA PILEOPSIS (Plate IX.).—Fig. 33 is a nearly round, smooth limpet, the outside being blackish, spotted with white, and the interior bluish, with a black margin. It is about an inch across.
Amongst the other ten Acmæa found in New Zealand the most noticeable is the Acmæa fragilis, a very delicate, thin, green shell, with narrow brown bands. There is a green ring in the interior of the shell. It is found under stones, and is about 1/2 inch across.