Pilinia rimosa Kützing, 1843b: 273 (type locality: near Cuxhaven, Niedersachsen, Germany).—Seagrief, 1984: 45.— Seagrief, 1988: 38.
INDIAN OCEAN DISTRIBUTION: South Africa.
Note: The troubled taxonomic history of this genus was reviewed by Papenfuss (1962), who showed that the attribution of hairs to this alga was erroneous. On the basis of this negative character and the presence of differentiated sporangia, he removed Pilinia from the Chaetophoraceae to the Chroolepaceae. He placed Sporocladopsis Nasr (1944: 34), which is based on S. erythraea Nasr from the Red Sea, in the synonymy of Pilinia. After examining the type collection of P. rimosa (in L) with the light microscope, Hooper, South, & Nielsen (1987) concluded that it was phaeophycean and, moreover, identical to Waerniella lucifuga (Kuckuck) Kylin in the Ectocarpaceae. O'Kelly (1989), after studying the ultrastructure of the type material of P. rimosa with the electron microscope, confirmed its placement in the Phaeophyceae, but new information about the sporangia caused him to reserve judgment regarding its relationship to other members of the class. Specifically, he interpreted the pluriseriate zoosporangial region, which previously had been considered to constitute a plurilocular sporangium, as a group of unilocular sporangia, each producing more than one zoospore, which are released through an exit papilla. In consequence of the assignment of Pilinia to the Phaeophyceae, the status of Sporocladopsis as a chlorophycean genus must be re-evaluated. A collection of S. novae-zelandiae V. Chapman (1949: 496, fig. 4; type locality: Bay of Islands, New Zealand) from New South Wales, Australia, determined by O'Kelly, was shown by Millar & Larkum (in Millar & Kraft, 1994b: 421) to have chlorophylls a and b characteristic of Chlorophyceae.