a Shells 
- New Zealand 
Plate V 
No. 24 
Plate VIII 
No.1 
species is an exceedingly rare one, resembling the Natica 
Zealandica in general shape, being globular, with a rela- 
tively large body whorl and a small spire. The outer lip 
is thin and sharp, and the interior 1s white and glistening, 
the inner lip with the columella and parietal wall forming 
an S, which accounts for its specific name, undulata, There 
is a thick white callus on the inner lip, which quite seals 
up the umbilicus. Suter remarks in his book that he has 
“seen no recent specimen, the description being taken from 
a fossil shell from Wanganui.” Fortune must have smiled 
upon me one morning, when I came across an empty shell 
in excellent condition, washed up on the ocean beach at 
Mount Maunganui after a south-easterly gale. The shell, 
which is about an inch in diameter, is a singularly beauti- 
ful one, of a pure snow-white, very thin, fragile, pellucid, 
sculptured only with the very faintest or growth lines, 
which are crossed by equally delicate spiral striations. The 
simplicity of design and the subdued scheme of decoration, 
instead of detracting from its charming appearance, render 
it the more alluring. As Thomson says :— 
“For loveliness 
Needs not the foreign aid of ornament, 
But is, when unadorn’d, adorn’d the most.” 
Cape Maria van Diemen; Mount Maunganui. 
LAMELLARIA OPHIONE (lamella, a thin plate; 
Ophion, one of the Titans) —An extremely thin, fragile, 
pellucid, small, white univalve. The aperture is large and 
widely open, almost the size of the entire shell, and, al- 
though a spiral, the whorls are coiled quite loosely; that 
is to say, the columella is not central and vertical, and, 
looking at the interior, one sees the whole of the internal 
surface. It is oval in shape, highly arched in the middle, 
somewhat after the fashion of the Pawa shell, and rather 
less than half an inch in length. The only sculpture is that 
of spirally-arranged growth lines. The animal is large, 
and the shell is invested in the mantle, a condition common 
to most other extremely thin and colourless shells, such as 
the Bubble shells and the Philine constricta. 
Auckland Harbour; The Snares; Mount Maunganui; 
Cook Strait. 
TRICHOTROPIS CLATHRATA (thrix, a hair; tropis, 
a keel; clathrus, a lattice). —A small ash-coloured, yellowish 
white or brown spiral univalve, about half an inch in height. 
Living shells are covered with an epidermis, fringed or 
hair-like at the keels, or ridges; and the sculpture consist- 
ing of spiral and axial ribs crossing each other at right 
48 
