Phylum: Rhodophyta   Family: Rhodomelaceae

Odonthalia dentata  (Linnaeus) Lyngbye, 1819

Northern Tooth Weed

Purple-red fronds to 300 mm long, branching distichous, disc holdfast. Found on rocks in lower intertidal pools and subtidally on the stipes of kelp. A north-western species

References: 
Maggs & Hommersand (1993) - Seaweeds of the British Isles, Volume 1 Rhodophyta, Part 3A Ceramiales;
Bunker, et al - Seaweeds of Britain and Ireland