Alvania gradatoides is a species of small sea snail with an operculum, a marine gastropod mollusk in the family Rissoidae.Bouchet, P. (2011). Alvania gradatoides (Finlay, 1930). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=565212 on 2012-07-25
Distribution New Zealand (off Oamaru) Tasmania
Description The length of the shell attains 3 mm, its diameter 1.6 mm.
Alvania gradatoides was originally discovered and described as Linemera gradatoides by Harold John Finlay in 1930.Finlay H. J. (1930). "Additions to the Recent Molluscan Fauna of New Zealand. No. 3." Transactions and Proceedings of the Royal Society of New Zealand. 61: page 222-247.
References
Powell, A.W.B. 1979 New Zealand Mollusca: Marine, Land and Freshwater Shells, Collins, Auckland Ponder, W.F. 1985 A review of the genera of the Rissoidae (Mollusca: Mesogastropoda: Rissoacea), Records of the Australian Museum ( Spencer, H.G., Marshall, B.A. & Willan, R.C. (2009). Checklist of New Zealand living Mollusca. Pp 196-219. in: Gordon, D.P. (ed.) New Zealand inventory of biodiversity. Volume one. Kingdom Animalia: Radiata, Lophotrochozoa, Deuterostomia. Canterbury University Press, Christchurch. Liu, J.Y. [Ruiyu] (ed.). (2008). Checklist of marine biota of China seas. China Science Press. 1267 pp.
External links http://www.mollusca.co.nz/speciesdetail.php?speciesid=620&species=Alvinia%20(Linemera)%20gradatoides