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

New Zealand Cenozoic Mollusca

Genus Attenuata Hedley, 1918


(Pl. 54c): Attenuata inflata (Laws, 1939); topotype, GS9730, Q8/f9828, Holland's Point, Pakaurangi, Kaipara Harbour (Otaian)

Beu & Maxwell (1990): Chapter 17; p. 380; pl. 54 c.

Synonymy: Nobolira Finlay, 1926; Adolphinoba Powell, 1930 (Ponder 1985, p. 76)

Classification: Rissoidae: Rissoinae

Description: Height 1.4-4.4 mm, ovate-conic to tall-spired. Protoconch dome-shaped, of about 1.5 whorls, sculptured with several simple spiral cords with minute interstitial granules. Teleoconch sculpture of prominent spiral ridges or keels and fine growth lines, a few species with low axial costae. Aperture ovate, peristome duplicated in most species; outer lip opisthocline, with varix.

Comparison: The prominent spiral teleoconch sculpture readily distinguishes Attenuata from most other rissoids; Lironoba Iredale, 1915 is similar, but has a much more weakly sculptured protoconch (almost smooth except for a weak keel and/or spiral lirae on the last whorl), and differs in radular characters (Ponder 1985, p. 75-76).

Distribution: Kaiatan-Recent, New Zealand; Late Eocene-Recent, temperate Australia (Ponder 1985, p. 77). Most Recent New Zealand species occur on the middle or outer shelf, or on the upper part of the slope.

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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