Valve clavate, with cuneate, acute apex; axial area distinct; central area unilateral with one stigma.
Blue clay.
Pl. [19], Fig. 11.
GOMPHONEMA ACUMINATUM VAR. TURRIS (EHR.) CL.
Valve clavate, with cuneate apiculate apex and narrow basis; axial area narrow, with a unilateral central space; stigma opposite the short striæ; striæ more radiate in the upper part, distant in the middle.
Smith's Island, Delaware River.
Pl. [19], Fig. 5.
GOMPHONEMA ACUMINATUM VAR. CORONATA (EHR.) CL.
Valve twice constricted, with broad, cuneate apex; striæ radiate in the middle, convergent near the apex and radiate at the apex. Variable in size and outline.
Blue clay. Fresh water. Common.