The Diatomaceæ of Philadelphia and Vicinity

by Charles S. Boyer

Pl. [19], Fig. 15.

GOMPHONEMA SARCOPHAGUS GREG.

Valve linear, irregular in outline, with rounded apex and basis; axial area distinct; central area small, unilateral, with one stigma; striæ irregular with coarse, distinct puncta.

Occasional in fresh water.

Pl. [19], Fig. 16.

GOMPHONEMA CAPITATUM EHR.

Valve clavate, broad at the sub-truncate apex and slightly constricted, or with parallel margins; axial area linear, central area stellate, with one stigma; striæ in the middle alternately longer and shorter.

Blue clay.

Pl. [19], Fig. 22.

GOMPHONEMA PARVULUM VAR. MICROPUS (KUETZ.) CL.