Phylum: Ochrophyta Family: Acinetosporaceae
Hincksia granulosa (Smith) P.C. Silva, 1987
Newton (as Ectocarpus granulosus) gives a growth length of 10-25 cm. and records it as common and abundant. Seaweeds of the South African South Coast records: "Thallus 0.5-3 (-6) cm high" - quite a range discrepancy."
It must be under-recorded as there are not many records. Both note it as epilithic and epiphytic
Newton (1931) - A Handbook of the British Seaweeds;
Anderson, Stegenga & Bolton (2016) - Seaweeds of the South African South Coast