Actinocyclus actinochilus (Ehrenberg) Simonsen (Figures 20, 21)

Literature: (Scott and Thomas 2005, p. 52, fig. 2.22a–f; Villareal and Fryxell 1983, p. 461, figs. 21–32).

Description: Diameter 36–61 µm, areole 6–13 in 10 µm.

Remarks: Areole arranged in radial rows in fascicules, length and number of areole rows inside fascicules vary between specimens and these are either straight or weakly undulate.

Ecology and distribution: This marine species has been widely reported around Antarctica under various synonyms. In his work on the Antarctic diatoms, Peragallo (1921) described Actinocyclus actinochilus under various new species names including Charcotia janus, C. bifrons, C. australis, C. valdiviae, C. castracanae, C. chromaradiatus, C. decrescens, C. irregularis, C. irregularis, C. disperses, C. micropunctatus, C. ornatus, and C. minor . These are in addition to several other names in other geographical locations (Simonsen 1982). Common in Potter Cove.