Pl. [7], Fig. 5 (somewhat inclined, as usually seen).
BIDDULPHIA SMITHII (RALFS) V. H.
Valve orbicular, convex, with reticulations 5 in 10 µ radiating from the centre and decreasing toward the margin and processes which are truncate. A short spine is found on each side half way between the processes. Zone narrow with fine puncta 12 in 10 µ in longitudinal rows.
Cerataulus smithii Ralfs.
Eupodiscus radiatus Wm. Sm.
Blue clay. Along the coast southward.
Pl. [7], Fig. 8.
BIDDULPHIA TURGIDA (EHR.) WM. SM.
Valve elliptical or orbicular, surface convex. Processes very large, cylindrical, placed obliquely and inclined by the torsion of the frustule. Between the processes are two stout spines, one on each side, frequently forked at the ends. Puncta fine, irregular at the centre and radiating toward the circumference.
Cerataulus turgidus Ehr.