Length: 30

Width: 9

Striae: 12

Collection 1565a

Stoerm. and Yang 1969 (Stoermer and Yang 1969).

DIC image

This specimen of Oestrupia zachariasi var. undulata was found in South Fishtail Bay, Douglas Lake, February, 1973 by Dr. Norman Andresen.

Douglas Lake specimen, DIC

Rarely found but more common than the nominate variety, this taxon has a similar distribution in the Great Lakes (Stoermer 1978).

Synonyms (Stoermer and Yang 1969)

Caloneis baltica var. undulata Schulz, Bot. Arch., 13:203, fig. 76. 1926.

Ecology