Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)
(Pl. 8h): GS9508, J40/f8803, McCulloch's Bridge, Kaiatan (GNS)
Beu & Maxwell (1990): Chapter 8; p. 127; pl. 8 h.
Synonymy: Uxia (?) marshalli Allan 1926, p. 342; Unitas marshalli
Classification: Cancellariidae: Cancellariinae
Description: Size moderate for family (height 10-19 mm), broadly fusiform, spire 0.5-0.6 total height. Protoconch depressed dome- shaped, of 3.5 whorls, apex almost flat, last 0.25 whorl with weak axial costellae and subobsolete spirals, remainder smooth. Teleoconch of 5-6 whorls, markedly convex on spire; last whorl strongly excavated, with a short neck. Sutures impressed at first, narrowly canaliculate on later whorls. Axial sculpture of very prominent rounded prosocline costae reaching from suture to suture on spire, and extending across base but not onto neck of last whorl; 10- 12 costae on last whorl; varices at irregular intervals. Spiral sculpture commencing as 3 narrow, rounded subequal cords, a fourth appearing out of lower suture during growth, and 4 or 5 additional cords appearing on last whorl; narrow, flattened threads also appearing between cords and elsewhere on later whorls. Cords crossing axial costae and varices with only slight thickening. Aperture ovate, columella almost straight, twisted to left abapically to form very short, unnotched siphonal canal, bearing 3 oblique plaits, the lowest one reduced to a low tubercle on largest specimen seen. Inner lip moderately thickly callused over columella, thinly in parietal area. Outer lip with a moderately heavy varix externally and 7 narrow lirae within.
Comparison: Fusiaphera naroniformis (Altonian, Oamaru) has a protoconch of only one whorl, distinctly shouldered teleoconch whorls, a less strongly impressed suture, and less prominent spiral sculpture. Both species were originally referred to Uxia Jousseaume, 1887 (now known by its replacement name Unitas Palmer, 1947) but they have more in common with the widespread warm-water genus Fusiaphera Habe, 1951.
Distribution: Kaiatan, Waihao Greensand, McCulloch's Bridge (type) (rare).
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
(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)