GNS Science

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

New Zealand Cenozoic Mollusca

Gemmula reticulata (Marshall, 1919)


(Pl. 6t): Hampden Beach, Bortonian (GNS, ex Marshall and Murdoch Colln.)

Beu & Maxwell (1990): Chapter 7; p. 110; pl. 6 t.

Synonymy: Turris reticulatus Marshall 1919, p. 231

Classification: Turridae: Turrinae

Description: Rather small for subfamily (height c. 25 mm), fusiform, spire about 0.6 total height. Protoconch not known, but probably conical with axial costae on the last 2 or 3 whorls. Teleoconch of 7-8 whorls, strongly angled at about 0.4 whorl height on spire, sutural ramp steep, concave with a low subsutural swelling; last whorl with weak peribasal subangulation, excavated below, probably with moderately long neck. Axial sculpture of prominent rounded or subrectangular peripheral nodules and much weaker, low nodules just below suture corresponding to those on periphery but set forwards; 12-16 nodules on penultimate whorl; other axial sculpture of growth lines. Spiral sculpture of narrow cords or threads, typically rather subdued, but in the figured specimen 1 cord between periphery and lower suture much more prominent than others. Aperture broken in available specimens, but presumably pyriform with a moderately long, unnotched siphonal canal; inner lip distinctly impressed posteriorly; outer lip apparently thin, smooth within; anal sinus deep, narrowly U-shaped, apex on peripheral keel.

Comparison: Gemmula reticulata is distinguished from other New Zealand species of Gemmula by having the peripheral keel angled rather than rounded or flattened, by its relatively coarse peripheral tubercles, by its relatively fine spiral sculpture and by the absence of internal lirae on the outer lip.

Distribution: Bortonian, Hampden Formation, Hampden Beach (type) (uncommon).

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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