Length: 9

Width: 6

Striae:12

Collection 1574

For new variety combination, see Hamilton et al. (1992). For genera transfer see Williams and Round (1987).

This variety is an intermediate between Staurosira construens var. construens and Staurosira construens var. pumila(Patrick and Reimer 1966).

Synonyms (Patrick and Reimer 1966)

Fragilaria construens var. venter(Ehr.) Grun. in V.H., Syn. Diat. Belgique, p. 45, fig.

21b, 22, 23, 24b, 26a-b. 1881.

Fragilaria venter Ehr. 1854.

Ecology

This species is widely distributed in waters with low nutrient levels(Patrick and Reimer 1966).

Length is 5-9 micrometers (Patrick and Reimer 1966).

Breadth is 3-6 micrometers (Patrick and Reimer 1966).

Striae range is 14-17 per 10 micrometers (Patrick and Reimer 1966).

In Lake Michigan samples, the length does not exceed 10 micrometers (Stoermer and Yang 1969).