Pl. [30], Fig. 24.
Tabellariæ
PINNULARIA STOMATOPHORA (GRUN.) CL.
Valve linear, with rounded ends; axial area less than one-third the width of the valve, gradually widened in the middle to a transverse fascia; on each side of the central nodule is a lunate space; striæ divergent in the middle, convergent at the ends, 13 in 10 µ; terminal fissures very long, bayonet shaped. L. 75 µ.
Cleve describes a variety continua as not interrupted. In some forms the fascia is marked by very faint, short striæ on the margin.
Fresh water. Newtown Square.
Pl. [30], Fig. 12.
PINNULARIA GIBBA (KUETZ.) V. H.
Valve linear, tapering to the subcapitate ends; axial area dilated in the middle; striæ, 10-11 µ, divergent in the middle, convergent at the ends. L. 80 µ.
Fresh water.