Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)
(Pl. 54b): Pisinna subtilicosta (Marwick, 1928) (synonymised with P. micronema (Suter, 1898) by Ponder (1965c, p. 141) but probably distinct); topotype, GS 12172, CH/f4B, Titirangi, Chatham Island (Nukumaruan) (apex showing traces of spirally arranged punctae on protoconch).
(Pl. 54g): Pisinna subtilicosta (Marwick, 1928) (synonymised with P. micronema (Suter, 1898) by Ponder (1965c, p. 141) but probably distinct); topotype, GS 12172, CH/f4B, Titirangi, Chatham Island (Nukumaruan)
Beu & Maxwell (1990): Chapter 17; p. 380; pl. 54 b,g.
Synonymy: Estea Iredale, 1915; Microestea Ponder, 1965
Description: Height 1.5-5.1 mm, pupiform, spire moderately elevated. Protoconch dome-shaped, of 1.5-2 whorls, with minute, shallow pits (punctae), in some species aligned in spiral rows. Teleoconch whorls typically flat-sided or gently convex, periphery usually rounded, angulate in a few species. Some species smooth, others axially costate or costellate, a few with spiral grooves or cords. Aperture oval or circular, flared; peristome continuous, sharp-edged, attached to last whorl in parietal region but partly detached (separated from columella by groove) below.
Comparison: Most species of Pisinna (some of them living sympatrically) inhabit very shallow waters (including intertidal coralline turf and mud flats) but others occur in much deeper waters (across the shelf and into the upper bathyal zone). Readily distinguished from other rissooideans by its apertural characters, Pisinna was long considered to be a rissoid, but it is now classed in the Anabathridae (Spencer et al. 2009). New Zealand species (living and fossil) were revised by Ponder (1965c) but a considerable number of additional fossil forms (some of them highly distinctive) are now known.
Distribution: Waitakian-Recent, New Zealand; Early Miocene-Recent, Australia, tropical West Pacific; Recent, Mediterranean, South Africa.
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)