47 Patella pellucida. Growth stage 5 (late adult) on Laminaria hyperborea frond. January 2016. Sublittoral. Egersund, S. Norway. © E. Svensen.

Those that survive as later-adults (GS5f) on fronds continue to have blue rays all around the shell as it grows, and a few, such as this, gain sufficient height to approximate to a Phrygian cap in profile.

 

Concise Key id. features: 1Pp flic.kr/p/Z4FxDe

Part 1, SHELL FORMS: 2Pp flic.kr/p/Z4FxAi

Part 2, BODY & ANATOMY: 3Pp flic.kr/p/Z4FxtK

Part, 3 HABITS & ECOLOGY: 4Pp flic.kr/p/Z4Fx9M

Sets of OTHER SPECIES: www.flickr.com/photos/56388191@N08/collections/

Done