References:
Archibald, R.E.M. & Schoeman, F.R. (1984). Amphora coffeaformis (Agardh) Kützing: a revision of the species under light and electron microscopy. S. Afr. Jour. Bot., 3 (2), Pg. 94, Figs 62-64;
Description:
Frustule lanceolate with protracted, rostrate poles. Girdle bands very finely striate. Valves semi-lanceolate, somewhat elongate. Dorsal margin convex, sometimes slightly flattened at the centre, ventral margin generally straight, sometimes slightly tumid at the centre or weakly concave. Raphe filiform, located close to the ventral margin. Raphe branches slightly sloping upwards from the poles to the central nodule, central pores small, but visible under LM, proximal and distal ends dorsally deflected. Axial area very narrow, linear, central area absent on the dorsal side, on the ventral side bounded by the ventral striae. Transapical striae on the dorsal side with indistinct structure, straight at the centre, becoming slightly radiate and denser towards the poles. Ventral striae uninterrupted at the centre, hardly visible under LM, very dense.
