From Fensome et al., 2019:
Deflandrea phosphoritica ssp. australis Cookson and Eisenack, 1961b, p.39–40, pl.1, figs.2–3. Holotype: Cookson and Eisenack, 1961b, pl.1, fig.2. Age: Eocene.

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Original description: [Cookson and Eisenack, 1961b]:

Deflandrea phosphoritica subsp. australis subsp. nov.
(Plate I, Figs. 2, 3: holotype Fig. 2 Nat. Mus. Vict. P20537)

Specimens which differ in certain constant characters from typical examples of D. phosphoritica are not uncommon in the Rottnest deposit between 1,480 and 1,541 feet. However, these features do not seem of sufficient importance for specific separation. A new subspecies is therefore proposed for them on the basis of the following differences from the type: - (a) the theca is proportionally longer
narrower: (b) the outer membrane is more closely and coarsely granular especially in the apical and antapical regions; (c) the horns are
more sharply pointed; (d) the apical horn is surmounted by a well-defined solid cylindrical process; (e) the longitudinal furrow is more
clearly marked and can be traced downwards from the lower borders of the girdle, the left hand ridge sometimes being straighter than the right hand one.

Dimensions.
Type - length 94 μ, breadth 94 μ, internal body 71 x 804 μ.
Range - length 105-146 μ, breadth 83-102 μ.