Rough Periwinkle (Littorina saxatilis) - Barns Ness, Dunbar, East Lothian, Scotland. No idea what the gelatinous black stuff is.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/35142635@N05">Silversyrpher</a> from Scotland, UK
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/35142635@N05/5041730256/">Rough Periwinkle (Littorina saxatilis)</a>