Description: Test nearly spherical; two chambers are externally visible. Proloculus followed by a planispiral tube of one or two windings, succeded by three or more opthalmidium type chambers; then several strongly embracing hemispherical chambers are added spirally in a plane that is perpendicular to the initial spire; less than two of the sub-globular chambers complete one whorl (i.e. each chamber encircles about 200° to 260° of a whorl). The largest tests comprised at least 8 subglobular chambers. Aperture is initially a round opening at the end of a slightly protrudin neck, then forming a cresecentic slit with a raised rim, gradually becoming more elongated and evenly curved, with a raised flap along the base, and an everted lip along the opposite rim. Test walls are thin and very fragile, surface is smooth and polished and suture nearly flush but distinct. The diameter of the largest specimen is 3,2 mm.
Diagnosis: Pyrgoella sphaera differs in having multiple apertures, comprising irregular openings and slits, instead of a single regularly curved slit. The species Pyrgoella irregularis differs in having a much thicker and sturdier walls, and a much shorter apertural slit with thickened rims and without developing everted lips as the present species.