The normal maximum shell height of L. littorea is about 30 mm. So this red specimen is a large one at 31.2 mm. Red ones are much less common than grey, brown or black ones in Europe, and they are absent from North America.
The brown and white specimen is a giant with a height of 50.3 mm. The cause of its giantism may be infection by a parasite that castrates its host and prevents reproduction which is often followed by death, so it survives and continues growth. Its spire and body whorl are mined by the boring sponge, Clione celata.
Orkney, Scotland. April, 1974.