Art. XIV.—The First-discovered New Zealand Gundlachia
[Read before the Wellington Philosophical Society, 7th September, 1904.]
Gundlachia neozelanica, n. sp.
Ancylus, sp., Suter, Journ. de Conch., vol. xl., pp. 248–250 (1892). Ancylus tasmanicus, Suter, P.L.S. N.S.W. (2), vol. vii., p. 624 (1893), (not of T.-Woods). Gundlachia, sp., Suter, Trans. N.Z. Inst., vol. xxvi., p. 122, pl. xiv., figs. 1–5 (1894); Gundlachia, sp., Suter, P.L.S. N.S.W. (2), vol. viii., p. 486 (1894); Gundlachia, sp., Hedley, l.c., pp. 505, 507, 511, pl. xxiv., figs. 12–15; Gundlachia, sp., Suter, Journ. de Conch., vol. xli., p. 229 (1894).
Shell depressed-conoidal, oval-oblong, thin, subtransparent, horn-colour, with a blackish-green coating; apex a little inclined to the right, situated at the posterior sixth of the length, flatly convex anteriorly; concentric lines of growth at regular intervals. Interior light-brown, shining; aperture elongated-oval, slightly broadened anteriorly. Length, 3 mm.; breadth, 2 mm.; height, ¾ mm.
Hab. River Avon, near Christchurch.
Type in my collection.
With regard to the dentition I have to rectify a mistake in the figure: the rhachidian tooth is bicuspid, not tricuspid.
The formation of a septum has been described and figured by Hedley (l.c.) from specimens I sent him.
I always hesitated giving this species a name, as I hoped fully developed specimens might turn up. This, however, has not been the case, and, as a second species has been discovered, it is incumbent to name the first-discovered form.