35 Patella pellucida. Length 9.2mm. Growth Stages 4 holdfast dweller (GS4h). March 2017. West Anglesey, Wales.

35 Patella pellucida. Length 9.2mm. Growth Stages 4 holdfast dweller (GS4h). March 2017. West Anglesey, Wales.

The exterior surface of holdfast dwellers is less smooth than that on frond and stipe dwellers, and it often has epizoic growths.
On this specimen, the blue rays of the juvenile shell continue less brightly on adult growth all of the way to the posterior edge.
This GS4 shell has yet to acquire the thicker inner layer usual on GS5 shells, and its muscle and mantle scars are indiscernible. Its height is 37% of the length.

Concise
Part 1, SHELL FORMS: 02 Patella pellucida. Growth Stage 2 (GS2). July 2012. Littoral. North Yorkshire, England. © P. Lightfoot.
Part 2, BODY & ANATOMY: 03 Patella pellucida. Growth Stage 3 (GS3). 2009. Sublittoral, Farne Islands, Northumberland, England. © P.Lightfoot.
Part, 3 HABITS & ECOLOGY: 04 Patella pellucida. Length 4.6mm. Growth Stage 3 (GS3). September 2016. Yorkshire, England. © P.Lightfoot.