Neidium hitchcockii

Valves are linear-lanceolate with triundulate margins. Undulations are more distinct on larger specimens, and still visible, but less pronounced on smaller specimens. The undulations are roughly equal in width, and encompass the majority of the valve margin. The valve ends taper to cuneate, apiculate apices. Relatively broad longitudinal canals are present along the valve margins. The raphe and axial area are linear and are bordered by a distinctive conopeum-like structure. Proximal raphe fissures are long, extending to, or at, the edge of the central area. The fissures are prominently deflected in opposite directions. The angle of deflection is variable, from 45° to 90°to recurved. Distal raphe ends are filiform. The central area is small and transversely oblong. Striae are punctate, parallel to slightly radiate, and become slightly convergent at the apices. Voigt faults are often, though not always, present.