Description: Thallus known only as unattached branching systems up to 35 mm in diameter.

Habitat: Sublittoral, on mobile substrata in harbours.

Distribution: Known only from Co. Galway in Ireland.

Distribution Map from NBN: Lithophyllum hibernicum at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Lithophyllum hibernicum at iNaturalist World Species Observations database.

WoRMS: Lithophyllum hibernicum at World Register of Marine Species. Accepted name: Lithophyllum hibernicum Foslie, 1906. AphiaID: 145151.

Classification: Biota; Plantae; Biliphyta; Rhodophyta; Eurhodophytina; Florideophyceae; Corallinophycidae; Corallinales; Corallinineae; Lithophyllaceae; Lithophylloideae; Lithophylleae; Lithophyllum