Lemmermann (1908: 28, fig. 95)
Takahashi (1991: figs 2-4, 15)
Dictyocha fibula Ehrenb. sensu Hallegraeff 2005: 251, Figs 4.1a-b
Cells uniflagellate. Silica skeleton cap-shaped, comprising a large rectangular or rhombic ring 18-39 microns diam., with 4 large spines radiating from the corners of the ring, radial spines longer than equatorial ones. Lateral rods of the basal ring with or without lateral spines or micro-spines. Connecting bars emanate asymmetrically from each side of lateral rod, arching upward and forming 4 windows. Apical bar is usually 1/2 to 3/4 length of the major basal ring, Apical spine long, oriented straight upward.
Southern Ocean between Australia and Antarctica.
The images in Antarctic Marine Protists (2005: 252, Figs 4.1a-b) were initially identified as Dictyocha fibula.
Another 4-spined cell, Dictyocha antarctica Lohmann, has been reported from the South Atlantic (Throndsen, 1996), but its radiating spines are significantly smaller.
There is evidence of plasticity of skeletal configuration in this genus (van Valkenberg 1980, Hendricksen 1993).