Litosiphon pusillus (Carmichael) Harvey
Description: Thallus filiform, olive when young, brownish when older, in tufts to 120 mm long. Filaments unbranched, 0.25-1mm diameter. Thallus mainly parenchymatous, uniseriate near the base. Parenchymatous parts differentiaed into medulla and epidermis; older parts of the frond become hollow. Haris abundant. Many discoid chloroplasts per cell. Unilocular sporangia developed from the the outer epidermal cells; plurilocular sporangia multiseriate, also developed from the outer epidermal cells.
Habitat: Lower intertidal, epiphytic on the brown alga Chorda filum.