GNS Science

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

New Zealand Cenozoic Mollusca

Mesoginella harrisi (Cossmann, 1899)


(Pl. 22a): GS9520, J41/f8029, Awamoa Creek, Oamaru, Altonian (GNS)

Beu & Maxwell (1990): Chapter 11; p. 207; pl. 22 a.

Synonymy: Marginella (Glabella) ovata Harris 1897, p. 88 (not of Lea, 1833); Marginella harrisi Cossmann 1899, p. 88 (new name for M. ovata Harris, preoccupied); M. (Kogomea) harrisi; Phyloginella harrisi; Deviginella (?) harrisi, Beu & Maxwell 1990, p. 207, pl. 22a.

Classification: Marginellidae

Description: Size moderate for family (height 4-7 mm), ovate, spire low, rounded-conic, 0.1-0.15 total height. Sutures largely obscured by callus, weakly impressed; teleoconch of about 2.5-3 whorls, spire whorls very gently convex; last whorl convex, with well rounded periphery, on some shells feebly excavated anteriorly. Surface polished, no sculpture. Aperture narrow, anterior end truncate or slightly convex, no notch or sinus. Inner lip callus thin, very difficult to discern in most shells, spreading around top of aperture and apparently along back of outer lip. Columella with 4 prominent plaits, the anteriormost bordering the short siphonal spout. Outer lip swinging forwards slightly at posterior end forming a shallow sinus; thickened externally, somewhat bevelled, inner edge smooth or weakly denticulate.

Comparison: Mesoginella harrisi is easily distinguished from Protoginella conica, with which it occurs at many localities, by its ovate shape, its rounded periphery and its narrower aperture. Mesoginella (?) coxi (Waipipian, Pitt Island) is very similar but differs in being more strongly convex and in having a less elongate last whorl.

Distribution: Waitakian-Altonian; Mount Harris Formation, Awamoa, Oamaru, Altonian (type) and other Altonian localities in Oamaru district; Otekaike Limestone, Trig Z, Otiake; Campbell Park School, Otekaike Valley, common or abundant at most localities.

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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