lowed (o coiiNfitiilc an .'Uioinalou.s Hpreies. It i« a 
iialive of llie McdilciKUieaii sea, and i olwci ved to 
KWim on llio Hiiilaec in tlio inannei of tlic genus 
(dio among llie Mollusca, to wliieli ils iidiabitlng 
animal is mucli allied. 'I In; usual Icnglli oftlic shell 
is iVom one to (wo-thirds of an ineli, and its colour 
a very pale yellowish hrowii. 
