GNS Science

Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)

New Zealand Cenozoic Mollusca

Alcithoe bathgatei Finlay, 1926


(Pl. 26b): GS11182, D45/f8819, Fouraye Siltstone, Clifden, Altonian (GNS)

Beu & Maxwell (1990): Chapter 11; p. 232; pl. 26 b.

Synonymy: Alcithoe bathgatei Finlay 1926b, p. 248; Waihaoia (Waihaoia) bathgatei; Alcithoe (Leporemax) bathgatei, Beu & Maxwell 1990, p. 232, pl. 26b.

Classification: Volutidae: Zidoninae

Description: Size moderate for genus (height 45-60 mm), slender, fusiform, spire about half total height. Protoconch depressed-cylindrical, of about 2 whorls, first whorl highly compressed with narrowly rounded periphery, in most specimens overhanging second whorl. Teleoconch of 5-6 whorls, early whorls gently convex, later whorls becoming progressively more strongly angled at about half whorl height, sutural ramp steep, slightly concave; last whorl weakly subangled about halfway between shoulder angle and anterior end, straight or feebly concave below. Axial sculpture of prominent, narrow-crested costae with much wider interspaces, reaching from suture to suture on spire whorls and about halfway across base of last whorl; 12-16 on penultimate whorl. Costae becoming tubercular on shoulder angle on last whorl (or somewhat earlier on some shells), strength of tubercles variable, but not strongly projecting in any specimens seen. Spiral sculpture of weak grooves on early whorls, later whorls of well-preserved shells with very numerous, microscopic striae. Aperture elongate-ovate, columella with 4 narrow plaits, the anterior one weaker and more oblique than the others, some shells with a fifth, weak plait at posterior end. Siphonal notch rather shallow; fasciole low, rounded.

Comparison: Alcithoe bathgatei is distinguished from other species by its small size, its slender shape, its tall spire and its axial sculpture of narrow-crested costae with small tubercles developed on the shoulder angle. A comment on the status of Leporemax is provided under A. lepida.

Distribution: Altonian, Fouraye Siltstone, Clifden (type) (moderately common).

Cite this publication as: "A.G. Beu and J.I. Raine (2009). Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990). GNS Science miscellaneous series no. 27."
© GNS Science, 2009
ISBN 978-0-478-19705-1
ISSN 1177-2441
(Included with a PDF facsimile file copy of New Zealand Geological Survey Paleontological Bulletin 58 in CD version from: Publications Officer, GNS Science, P.O. Box 30368 Lower Hutt, New Zealand)


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