Mask shell

Mask´ shell`

1.(Zool.) Any spiral marine shell of the genus Persona, having a curiously twisted aperture.
References in periodicals archive ?
EFP has received approximately half of the 300,000 mask shells ordered from its Taiwanese manufacturer; the balance of the 300,000 shells order is expected to begin shipment from Taiwan the week of Jan.
Concurrently, the company expects to receive 50,000 mask shells from Taiwan and has placed an initial order for an additional 100,000 mask shells from its Taiwanese supplier.