GNS Science

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

New Zealand Cenozoic Mollusca

Cominella (Procominula) denselirata (Finlay, 1926)


(Pl. 15j): Trig Z, Otiake, Waitakian (GNS, from an early collection)

Beu & Maxwell (1990): Chapter 10; p. 160; pl. 15 j.

Synonymy: Cominula (Procominula) denselirata Finlay 1926b, p. 242-243

Classification: Buccinulidae

Description: Small for genus (height 12-14 mm), ovate, spire a little less than half total height. Protoconch dome-shaped, of 1.2 strongly convex whorls, smooth except for a few weak axial costellae on last quarter-whorl. Teleoconch of 4.5 whorls, obtusely angled near middle on spire; last whorl excavated, with short neck. Axial sculpture of narrowly rounded costae with broad, concave interspaces, prominent from lower suture to shoulder angle on spire, but weaker or obsolete on ramp; barely persisting onto base; 8-10 costae on penultimate whorl. Spiral sculpture of numerous narrow, rather subdued cords with narrower interspaces, some shells with a slightly stronger cord on periphery. Aperture rather small with a short, left-deflected siphonal canal, notched anteriorly, forming a low fasciole. Outer lip smooth or finely lirate within.

Comparison: The subgenus Conimella (Procominula) includes distinctive buccinulids similar to Cominella (sensu stricto) but of smaller size and having a rather better-defined siphonal canal, and is recorded so far only from mid-shelf to upper bathyal assemblages from North Otago and South Canterbury. C. denselirata differs from the other species primarily by its fine spiral sculpture.

Distribution: Waitakian; Otekaike Limestone, Trig Z, Otiake (type) (moderately common); Campbell Park School (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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