This species lives in slightly alkaline fresh water. It is sometimes found in slightly brackish water (Patrick and Reimer 1966). The growth and habitat preference are similar to those of the nominate variety (Stoermer and Yang 1970); however this species is generally considered to have larger abundances in more eutrophic areas compared to the nominate variety (Stoermer and Yang 1970).
This species is generally less common than the nominate variety in Lake Michigan studies. The low abundances have been consistent since 1879 (Stoermer and Yang 1970).
This variety is distinguished from the other varieties of this species by the constriction in the middle of the valve ( Patrick and Reimer 1966). The central area is usually a hyaline fascia (Stoermer and Yang 1969).