Pinnated, winged.

Plaited, folded.

Plaits, folds.

Plicated, folded or plaited, as in the pillar of the volute tribe.

Plumose, having a feathery appearance.

Polythalmous, divided into several chambers.

Porcate, marked with raised longitudinal lines.

Porrected, projecting.

Prismatic, generally applied to the colours of shells, being like those of the prism; iridescent.

Produced, lengthened out.