GNS Science

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

New Zealand Cenozoic Mollusca

Genus Crosseola Iredale, 1924



scale

(Pl. 53e): Crosseola sinemacula (Laws, 1939); topotype, GS9730, Q8/f9828, Holland's Point, Pakaurangi, Kaipara Harbour (Otaian) (apex showing protoconch and teleoconch microsculpture of granules between main sculptural elements).
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scale

(Pl. 53h): Crosseola sinemacula (Laws, 1939); topotype, GS9730, Q8/f9828, Holland's Point, Pakaurangi, Kaipara Harbour (Otaian)

Beu & Maxwell (1990): Chapter 17; p. 376; pl. 53 e,h.

Synonymy: Genus Crossea A. Adams, 1865, subgenus Crosseola Iredale, 1924 in Beu & Maxwell 1990, p. 376.

Classification: Skeneidae

Description: Height 1.4- 4.3 mm, globose or turbiniform, rather solid; protoconch cap-shaped with microsculpture of fine anastomosing ridges; teleoconch whorls strongly convex or keeled, sculpture clathrate or of prominent spiral cords or keels crossed by weaker axial costae, or of spiral striae. Microsculpture of minute granules between main sculptural elements. Aperture circular, base of inner lip with a short, oblique channel (better-developed in juvenile than in adult shells in some species) forming a prominent rounded fasciole bordering a narrow pseudumbilicus.

Comparison: Crosseola is distinguished from other skeneids primarily by the anterior notch or channel and the prominent fasciole. Crossea differs from Crosseola in having prominent varices on the adult whorls but is otherwise similar. Dolicrossea Iredale, 1924 (Elachisinidae) is distinguished mainly by its more elongate shape, by its much weaker sculpture (of incised spiral grooves), and by its narrow, crescentic umbilicus, which is bounded on its inner edge by a narrow ridge.

Distribution: Otaian-Recent, New Zealand; Recent, south-eastern Australia. Most modern records are from middle to outer shelf or upper bathyal depths, but some species occur in shallower waters.


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)

References

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