1: short, unglazed, chalky-white central line on whitish projecting points of ribs.
2: opaque-white line within translucent, horseshoe-shape, pedal-retractor muscle scar (on many, but not all, P.depressa specimens).
3: orange-cream amphora-area enclosed by scar of pedal-retractor muscle.
4: transparent pallial-skirt shell-layer and insert of magnified section to show iridescent lines caused by crystalline structure.

OTHER SPECIES ALBUMS
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