The valve of this taxon is elongate with convex sides and is tapered to rounded ends. It has a straight raphe valve that narrows at the ends. Its proximal ends curve in opposite directions and the central area of the taxon is elliptical. The striae are punctuate and they are oblique. The striae radiate in the middle of the valve but become parallel at the ends. It is variable in form and structure (Patrick and Reimer 1966).
USA, New York, West Point, New England, Middle Atlantic States, Southeastern USA, Gulf Coast, South Central States, East Central States, West Central States, Lakes States, Plains States, Wyoming, Washington, Oregon, California (Patrick and Reimer 1966).
This taxon prefers slow or not moving water. It is found in lakes, ponds, and bogs. It is ph indifferent and is considered to be oligosaprobic (Patrick and Reimer 1966; Lowe 1974 ).