Pl. [26], Fig. 3.
NAVICULA SPICULA (HICKIE) CL.
Valve narrow, lanceolate with acute ends; axial area narrow, central area dilated into a stauros reaching the margin; transverse striæ, 25-29 in 10 µ, longitudinal closer. L. 50-130 (Cl.).
Sometimes confused with N. crucigera.
Stauroneis spicula Hickie.
Newark, N. J.
Pl. [26], Fig. 4.
NAVICULA CRUCIGERA (WM. SM.) CL.
Valve lanceolate, narrow, with acute apices; central nodule a stauros reaching the margin but crossed by two or three coarser striæ; transverse striæ, 12 in 10 µ, punctate, the puncta about 25 in 10 µ. L. 80-100 µ (Cl.). Frustules in gelatinous tubes or free.
Schizonema cruciger Wm. Sm.