Pl. [30], Fig. 5.
PINNULARIA MESOGONGYLA (EHR.) CL.
Valve linear, gibbous in the middle, ends subcapitate; axial area narrow, widened in the middle to a large orbicular space; striæ strongly divergent in the middle, convergent at the ends, 11 in 10 µ. L. 60 µ.
Fresh water. Common.
Pl. [30], Fig. 6.
PINNULARIA STAUROPTERA (GRUN.) CL.
Valve linear, with slightly triundulate margins tapering to the subcapitate ends; axial area more than one-third the width of the valve, slightly widened in the middle; median line with approximate central pores and semicircular terminal fissures; striæ divergent in the middle, convergent at the ends, 11 in 10 µ. L. 82 µ.
May's Landing, N. J.
Pl. [30], Fig. 13.
Some of the forms are more triundulate than the specimen figured.