The upper of the 2 gastropods.
No interactions present.
Interesting how you have unnecessarily hyphenised here - this is the Dog whelk.
The other shell.. a dark variety of Gibbula umbilicalis?
Id agree with G. umbilicalis for the topshell, the barring is much too broad for G. cineraria.
On watch as always...
I find it interesting that when one wakes up a post, say with a comment or agreement, lots of good people come!
This post has been silent for nearly a year.
Welcome to ChrisMcA too, who we can thank for my trawl of whelks and winkles!
Gramandy was moaning, in another similar post, about common name database, which is why I noted his hyphen.
Lat/Lng: 51.3834, 1.3206
OS grid ref: TR311701
mid eulittoral on chalk reef