The Diatomaceæ of Philadelphia and Vicinity

by Charles S. Boyer

NAVICULA LATISSIMA VAR. ELONGATA (PANT.) CL.

Valve elliptical-lanceolate, with rounded ends; striæ and puncta closer than in the type form; axial area narrow, widened in the middle; terminal fissures hook-shaped, turned in different directions.

Navicula humerosa var. elongata Pant.

Fossil at Buckshutem, N. J.

Pl. [24], Fig. 5.

NAVICULA FUCHSII PANT.

Valve elliptical, with slightly produced apices; axial area wide, lanceolate; central area orbicular; striæ alternately longer and shorter in the middle, 10-12 in 10 µ; puncta on the border of the axial area larger, elongated; median fissures incrassate.

Navicula humerosa var. fuchsii (Pant.) Cl.

Navicula (latissima var.?) fuchsii Pant.

Port Penn, Delaware River.