is pear-shaped, rounded below and channelled above. The 
most striking feature of this little shell is the presence of 
three plaits on the imner side of the mouth, the smallest 
one below, a medium-sized one above it, both on the col- 
umella, and a third one higher again, sloping downwards 
and reaching half across the aperture. It is about one- 
third of an inch in height. 
Massacre Bay; Bay of Islands; Auckland; Mount 
Maunganui; Banks Peninsula; Chatham Islands. 
PUPA GRACILIS (pupa, a chrysalis: gracilis, grace- 
ful)—An elongated pure white spiral univalve with an 
exceptionally tall body whorl and a short spire. The 
sculpture consists of fine striations disposed spirally, with 
rather broad and flat intervening spaces. The aperture, 
which is not quite the same height as the spire, is narrow 
above and broad below. The outline of the body whorl 
is almost straight except for a slightly waisted middle, 
wherein this species differs from the two other species, 
which have a decided outward bulge. The columella shows 
a strong doubie plait winding down to the basal lip, which 
is rounded and sharp. It is about three-quarters of an 
inch in height. The only place from which this species 
has been recorded hitherto is Wellington, but we have 
found five or six washed up at different times on the sandy 
beach at Mount Maunganui. 
AMPHIBOLA CRENATA (amphibolos, equivocal, 
having a double meaning; crenata, notched).—This is a 
pulmonate or air-breathing univalve, and occupies a unique 
position in the molluscan world. In colour one finds an 
artistic blending of yellows, browns and purples. It is 
globular in shape, rather like that objectionable pest, the 
garden snail, somewhat thin, with a small pointed spire, 
and there is a typical notch in the outer lip, corresponding 
to the angle of the body whorl. The inner lip is purple; 
the aperture is oval, the operculum thin and horny, the 
only instance where a pulmonate mollusc is found pos- 
sessing that structure. It lives in brackish water or salt 
water on mud flats, iri sea grass, at river mouths, in New 
Zealand. The animal feeds on vegetable matter contained 
in mud, large quantities of which are passed through the 
alimentary tract. In the breeding season one may find 
almost every shell surrounded by a broad flat ring of sandy 
mud. These casts are the spawn coils, curved on the flat, 
rounded above and slightly concave on the under surface. 
They contain the eggs, which may be examined by teasing 
out portions of the nest in sea water under a magnifying 
81 
Plate V 
No. 15 
Plate VIIT 
No. 24 
Sea Shells 
of New Zealand 
