Phylum: Rhodophyta   Family: Colaconemataceae

Colaconema infestans (M.A. Howe & Hoyt) Woelkerling, 1973

'Plants consisting of uniseriate filaments, endozoic in the inner layer of the perisarc of hydroids' - (Dixon & Invine, 1977). Thought to be widespread but under-recorded

References: 
Dixon & Irvine (1977) - Seaweeds of the British Isles, Volume 1 Rhodophyta, Part 1 Introduction, Nemaliales, Gigartinales