Borsonia zelandica is an extinct species of sea snail, a marine gastropod mollusk in the family Borsoniidae.Marshall, B. (2015). Borsonia zelandica (P. Marshall, 1919) †. In: MolluscaBase (2015). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=831617 on 2016-02-29
Description The spiral ornament consists of four wavy cords between the keel and the lower suture. The suture is margined by a stout swelling. There are 6 to 7 axials per whorl with wider interstices.Finlay, H. J. "New shells from New Zealand Tertiary beds." Transactions of the New Zealand Institute. Vol. 56. 1926
Distribution This extinct marine species was endemic to New Zealand
References
Maxwell, P.A. (2009). Cenozoic Mollusca. pp 232–254 in Gordon, D.P. (ed.) New Zealand inventory of biodiversity. Volume one. Kingdom Animalia: Radiata, Lophotrochozoa, Deuterostomia. Canterbury University Press, Christchurch.