Phylum: Rhodophyta   Family: Rhodomelaceae

Osmundea pinnatifida (Hudson) Stackhouse, 1809

Pepper Dulse

A variable species depending on the time of year and its position within the tidal zone. Dullish red and longer in sheltered sites but higher up the shore, shorter and yellowy-brown. Occasionally found covering large areas but more commonly along the edges of rock-pools

References: 
Fish & Fish (2011) - A Student's Guide to the Seashore;
Bunker, et al - Seaweeds of Britain and Ireland