Blue clay. Brackish water.

Pl. [34], Fig. 1.

In the specimen figured, the outline is exactly elliptical, although the species is usually conical at one end.

SURIRELLA GEMMA EHR.

Valve ovate or ovate-elliptical, rounded at each end, sometimes asymmetrical along the longitudinal axis; pseudoraphe very narrow; costæ distant, at irregular intervals, about 2 in 10 µ, somewhat radiate, reaching the pseudoraphe; striæ, 20 in 10 µ, punctate. Frustule in zone view cuneate. L. 70-120 µ.

Along the coast.

Pl. [36], Fig. 4.

SURIRELLA TENERA GREG.

Valve ovate; pseudoraphe narrow, well-defined; costæ indistinct, 2½ in 10 µ, their margins invisible; striæ about 14 in 10 µ, punctate, more evident near the margin. L. 90 µ.

Surirella diaphana Bleisch.