Schizoporella unicornis (sensu Wood, 1844, non Johnston, 1847)

Colonies are multiserial, forming unilamellar encrusting sheets.

Autozooids are slightly longer than wide, measuring 0.41-0.55 mm long by 0.33-0.47 mm wide, and rhomboidal in outline shape. The frontal shield is a convex cryptocyst, smooth or covered by minute granules and evenly perforated by pseudopores with marginal areolar pores that are somewhat more elongated than the pseudopores. A conical umbo is apparent in most zooids. The orifice is typically slightly broader than long, measuring 0.11-0.13 mm long by 0.10-0.12 mm wide, with a broad V-shaped sinus about one-third the length of the entire orifice. Condyles are elongate, spreading along the proximal edge of the orifice. Oral spines are lacking. Ovicells have not been observed.

Adventitious avicularia are generally paired, relatively short, 0.09-0.14 mm long by 0.05-0.07 mm wide, directed distolaterally and positioned laterally of the orifice with the proximal edge of the opesia level with the proximal edge of the sinus. The rostrum is triangular, with slightly concave edges, and the crossbar is calcified although typically broken in Crag specimens (in better preserved material from The Netherlands, the crossbar has a columella).