Zoœcia large and pentagonal, average length about 8 mm., markedly crater-shaped (i.e. with side walls sloping inwards to a deep-lying areal opening): areas sub-pentagonal as a rule : side walls wide, sloping inwards practically all the way from the zooecial margin, the slope gentle in the lower half, then changing gradually to quite steep at the upper end; the two upper corners are occupied by a pair of stumpy perforated tubercles; just below the summit of the steep inward slope at the upper end of the arc, close to the corners and probably communicating with the external tubercles, are two pores so faint as to be hardly visible in full light.