The Diatomaceæ of Philadelphia and Vicinity

by Charles S. Boyer

Amphiprora lepidoptera Greg.

Along the coast.

Pl. [14], Figs. 8 and 9.

Auricula CASTRACANE (1873)

(auricula, the ear, the shape of the valve)

Frustule globose. Valve reniform or cymbiform, elevated into a keel which is not sigmoid. Median line biarcuate. Differs from Amphiprora in not having a sigmoid keel.

AURICULA MUCRONATA (H. L. SMITH) PERAGALLO

In zone view, the median line deeply bisects the longitudinal axis, ending in a mucronate central nodule. Connective zone complex. Valve very complex, with ventral margin nearly straight and raphe excentric. Central nodule near the margin, terminal nodules small. Striæ, 35-40 in 10 µ (Cleve). Chromatophore single, on the ventral part.

Amphora mucronata H. L. Smith.

Amphora (?) insecta Grun.