Phenacomargarites williamsae is a species of sea snail, a marine gastropod mollusk, in the family Calliostomatidae within the superfamily Trochoidea, the top snails, turban snails and their allies.MolluscaBase (2018). Phenacomargarites williamsae B. A. Marshall, 2016. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=881096 on 2018-12-28
Description The shell has a turbinate shape, and attains a length of 22.1 mm. The shell has a silver/yellow color, with the aperture protruding in an arch shape.
Distribution This marine species occurs off the Solomon Islands.
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