Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)
(Pl. 8p): GS9508, J40/f8803, McCulloch's Bridge, Kaiatan (GNS)
Beu & Maxwell (1990): Chapter 8; p. 122; pl. 8 p.
Synonymy: Waihaoia allani Marwick, 1926a, p. 275; Beu & Maxwell 1990, p. 122, pl. 8p; Spinomelon allani, Maxwell 1992, p. 140
Type species of Waihaoia Marwick, 1926
Classification: Volutidae: Zidoninae
Description: Size moderate for genus (height 45-50 mm), fusiform, spire 0.4 total height. Protoconch of about 3 whorls when complete, but large, bulbous initial whorl missing from most specimens, leaving an apical spike. Teleoconch of 5-6 whorls; early whorls convex, later ones weakly shouldered near middle on spire; last whorl weakly excavated. Axial sculpture of narrow costae reaching from suture to suture on spire, though weakening somewhat on ramp, and extending about halfway across base of last whorl, slightly tubercular on shoulder angle on some shells; 13-17 on penultimate whorl. Spiral sculpture of very fine wavy striae, retained only on well preserved shells. Aperture elongate; siphonal notch shallow, fasciole rounded, weakly developed. Columella padded centrally, bearing 5 plaits, the abapical one the weakest. Inner lip thinly callused; outer lip slightly thickened, weakly convex.
Comparison: Spinomelon allani is distinguished from S. suteri (Bortonian(?), Waihao Forks) by its less strongly shouldered teleoconch whorls and by having five rather than four columellar plaits. S. thomsoni (Pl. 6n) has a more slender shell with axial costae changing into tubercles or becoming obsolete on later whorls.
Distribution: Kaiatan, Waihao Greensand, McCulloch's Bridge (type); Kapua Tuff, Waihao River. Rather uncommon at both localities. The poorly known Runangan species W. formosa (Trig M, Totara) may be a synonym.
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)