Hystrichosphaeridium choanophorum Deflandre and Cookson, 1955, p.271–272; text-figs.23–29. Emendation: Harland and Hill, 1979, p.39,41, as Melitasphaeridium choanophorum

Now Melitasphaeridium. Originally Hystrichosphaeridium, subsequently (and now) Melitasphaeridium.
Hystrichosphaeridium choanophorum was a nomen nudum in Deflandre and Cookson, 1954.
Taxonomic junior synonym: Melitasphaeridium aequabile, according to Harland, Head and Wrenn in Head and Wrenn (1992, p.10).
This name was not validly published in Deflandre and Cookson (1954, p.1236), since these authors did not provide a description.

Holotype: Deflandre and Cookson, 1955, text-figs.23-26
Paratypes: Deflandre and Cookson, 1955
Locus typicus: Hampton (near Melbourne), Victoria, Australia
Stratum typicum: Pliocene

Original description: Deflandre and Cookson 1955, p. 271
Shell globular, furnished with tubular processes not communicating with the interior. Processes cylindro-conical, abruptly widened into a small funnel with a rough margin, sometimes into a flat expansion with a finely denticulate
margin, or rarely, terminated by 2 recurved spine-like outgrowths. Membrane smooth or indistinctly granular.
Dimensions: Shell: 30-34 Ám; Processes: 15-17 Ám long; Overall diameter: 54-63 Ám.