Striæ, 14 in 10 µ, punctate, oblique in the middle, convergent at the ends; puncta, 15 in 10 µ. L. 238 µ.

Pensauken, N. J. (artesian well).

Pl. [21], Fig. 11.

Var. genuina forma minor Cl.—L. 26 µ; striæ, 24 in 10 µ.

Brandywine Creek.

Pl. [21], Fig. 12.

NEIDIUM AFFINE VAR. AMPHIRHYNCUS (EHR.) CL.

Valve linear, with protracted capitate ends; striæ transverse, interrupted by several longitudinal lines.

Willistown, Pa.

Pl. [21], Fig. 13.