Marine. Cape May.
Pl. [10], Fig. 37. Fig. 36 is an indeterminate form occasionally found in the blue clay.
FRAGILARIA CAPUCINA VAR. MESOLEPTA RAB.
Valve linear, constricted at the hyaline middle; apices slightly produced; striæ, 17 in 10 µ. Quite variable in size.
Schuylkill River. Morrisville (Keeley).
Pl. [10], Fig. 34.
FRAGILARIA HARRISONII (WM. SM.) GRUN.
Frustules rectangular, solitary or in twos. Valve cruciform; pseudoraphe narrow, lanceolate; striæ robust, radiating in the middle, composed of confluent puncta, larger at the circumference.
Blue clay.
Pl. [10], Fig. 31.