Art. XXXV.—On a New Shell (Anomia walteri).
[Read before the Wellington Philosophical Society, 20th February, 1895.]
Shell fragile, nacreous, with brilliant lustre and translucent Form irregular, the upper valve convex, corrugated, and often bullate. Structure lamellar, with faintly-marked wide ribs and wavy rays. On the interior surface a triangular area of white shell extends from the cartilage-pit to the middle of the valve, within which area are three distinct and equal-sized muscular scars. The cartilage-pit is single and straight, sub-marginal, and under a feebly-developed beak. The lower valve is horny and almost transparent, except an opaque white crescent round the notch. In form it is concave, and imbedded in the upper valve like an operculum. The notch is of a moderate size, with a strong anterior process which is hinged to the pit in the upper valve by a black ligament. The posterior margin is very thin. The shelly plug has not been preserved in any of the specimens. Colour: Upper valve rich honey-yellow, sometimes with pink tint; lower valve colourless.
Locality.—Pahia, Bay of Islands, Auckland.
A large number of specimens of this very beautiful shell were collected by Thomas Walter, Esq., to whom the species is dedicated. The same sea-beach is famous for the frequent occurrence of the rare and interesting shell Murex angasi.