Brandt, 1907 emend.
Diagnosis
Lorica from small and stout to elongate, conical, or chalice-shaped, usually with gutter between inner and outer laminae (mainly in larger species). With an aboral horn or pedicel. Lorica wall sometimes with very small fenestrae located between ribs. Oral rim always toothless.
Arranged in Subgroup 4E (see the page Ti. 15 Classification scheme based on morphologically similar groups of species).
Species treated (marked with * are dubious species):
*Rhabdonella amor (Cleve, 1900)
*Rhabdonella apophysata (Cleve, 1900)
*Rhabdonella chiliensis Kofoid and Campbell, 1929
*Rhabdonella cornucopia Kofoid and Campbell, 1929
Rhabdonella spiralis (Fol, 1881)
Further studies on the whole spectrum of forms of Rhabdonella are needed. The only consistent descriptions are those of *Rhabdonella apophysata, *Rhabdonella amor and Rhabdonella spiralis, but the presence or absence of a horn, or even the presence of a pedicel with either a skirt or a knob, or an incipient knob are not considered here to have diagnostic value (see genus Xystonellopsis).