04 Patella depressa. Length 28mm. Lleyn, Wales. September 2015.

04 Patella depressa. Length 28mm. Lleyn, Wales. September 2015.

Initially-sharp ribs rounded by erosion.
1: rib-points reduced by erosion on this stretch of aperture-rim.
2: outer shell-layer eroded away from the apical half of the shell (frequent on P.depressa).
3: rib-points not eroded on this stretch of aperture-rim.
4: dark radiating rays in grooves of the exterior shell-layer visible externally only on uneroded parts.
5: opaque, pigmented, chalk-white pallial tentacle protruding.

OTHER SPECIES ALBUMS
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