NAVICULA PUNCTULATA WM. SM.
Valve elliptical-lanceolate, with sub-rostrate ends; axial area narrow, central area rounded; striæ, 11 in 10 µ, closer at the ends, a few shorter in the middle; puncta, 10 in 10 µ. L. 54 µ.
Navicula marina Ralfs.
Port Penn, Delaware River (brackish water).
Pl. [25], Fig. 9.
"Although this species is described as marine in the Synopsis of Prof. Smith, I have never found it in purely marine localities" (Donkin).
NAVICULA PUNCTATA VAR. ASYMMETRICA LAGERSTEDT
Valve lanceolate, with rostrate ends; axial area narrow, central area transverse, irregular; striæ radiate, punctate, 12 in 10 µ. L. 36 µ.
Navicula amphibola Cleve.
Blue clay.