GNS Science

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

New Zealand Cenozoic Mollusca

Genus Pusillina Monterosato, 1884; Subgenus Haurakia Iredale, 1915


(Pl. 54f): Pusillina (Haurakia) chemnitzia (Laws, 1948); GS12600, 05/f21, Otueka hill road-cutting, Hokianga (Otaian)

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

Synonymy: Haurakiopsis Powell, 1937

Classification: Rissoidae: Rissoinae

Description: Height 1.6-3.3 mm, ovate- conic. Protoconch of 1.5 whorls with large initial whorl, or of about 2.5 whorls with small initial whorl; smooth or with spiral threads or rows of minute granules. Teleoconch smooth in some species, others with axial costae that stop at peribasal cord (i.e. not at periphery but some distance below) on last whorl. Some species with spiral striae over whorls, or weak spiral cords on base. Aperture ovate with a shallow anterior excavation, outer lip thin or with weak varix.

Comparison: Pusillina (Haurakia) is distinguished from other New Zealand rissoids by its ovate-conic shape and by the absence or weakness of spiral sculpture. Some weakly sculptured species resemble species of Powellisetia Ponder, 1964, but they differ in having an anteriorly excavated aperture. Powellisetia also differs anatomically from Pusillina (Haurakia) (Ponder 1985, p. 62). Rissoa (Haurakia) curvicostata (Grant-Mackie & Chapman-Smith, 1971) (Te Piki, Haweran) has a heterostrophic protoconch and a weak columellar plait, and was removed to the Pyramidellidae, tentatively to Chrysallida, by Beu & Maxwell (1990, p. 380).

Distribution: Waitakian-Recent, New Zealand; Oligocene-Recent, temperate Australia; Recent, South Africa, tropical Indo-Pacific (Ponder 1985, p. 30).

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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