Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)
| | Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990) |
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  (Pl. 8j): GS9508, J40/f8803, McCulloch's Bridge, Kaiatan (GNS) |
Beu & Maxwell (1990): Chapter 8; p. 121; pl. 8 j.
Synonymy: Vexillum plicatellum Marshall and Murdoch 1923a, p. 123; Proximitra (?) plicatellum; Parvimitra plicatellum; Parvimitra subplicatellum Finlay 1930b, p. 64-65; Parvimitra allani Finlay 1930b, p. 65-66; Conomitra plicatella; Peculator (Parvimitra) pliactellus, Beu & Maxwell 1990, p. 121
Classification: Volutomitridae
Description: Rather small for family (height 6-8.5 mm), biconic to broadly fusiform; spire of variable elevation but always less than half total height. Protoconch relatively large, of a little more than 1 smooth whorl. Teleoconch of 4-4.5 whorls, spire whorls moderately convex, often weakly shouldered near middle; last whorl contracted gradually, weakly excavated. Axial sculpture highly variable, in some shells consisting of prominent costae reaching from suture to suture on spire whorls, and persisting onto last whorl; in others costae becoming obsolete on 2nd or 3rd whorl; 15-24 costae on penultimate whorl. Spiral sculpture also variable but always present, ranging from subobsolete threads restricted to base and neck to moderately strong cords present over whole of teleoconch. Aperture narrowly pyriform, columella almost straight, typically bearing 4 narrow plaits, adapical one often weaker than the one below, abapical one much weaker than others and absent from a few specimens. Outer lip thin, smooth within, gently flexuous.
Comparison: Peculator pukeuriensis (Pl. 21p) is very similar to P. plicatellus, but differs in being thicker-shelled and in having more distinctly shouldered teleoconch whorls and, in most specimens, weaker spiral sculpture. Cernohorsky (1970a, p. 111) referred this species (but not P. pukeuriensis) to the Northern Hemisphere genus Conomitra Conrad, 1865, but it is not particularly like the type species of Conomitra and is in fact so close to P. pukeuriensis as to make assignment to a different genus unwarranted. P. pukeuriensis is the type species of Parvimitra Finlay, 1930, which was regarded as a synonym of Peculator Iredale, 1924 by Maxwell (1992, p. 137).
Distribution: Kaiatan, Waihao Greensand, McCulloch's Bridge (type locality of all three nominal species).
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
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