Description: Varies from sheets or cushions of unequal thickness to massive-lobose. The lobes may become elongate and anastomose, leading to a superficially ramose appearance. Specimens can grow to a considerable size - at least 10cm diameter and thickness. Yellow, yellow green. "A live, ochrous yellow (never red)"; "pinkish grey". "Preserved, white to light brown". Firm to soft, even. "Firm, compressible". "Oscules few, large when open, found at summits of the lobes or scattered and carried on membraneous fistules on encrusting forms".

Habitat: "Littoral to 37m, growing on stones, shells, algae, sessile coelenterates and Chlamys varia". On boulders, cobble, at sheltered sites with moderate tidal streams.

Distribution: "British Isles. Common along the Atlantic coast of France and Spain; Mediterranean". Azores.

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

iNaturalist: Mycale contarenii at iNaturalist World Species Observations database.