Actinoptychus cellulosa Ehr., H. L. Smith Sp. Typ., 384.
Quite common in marine and brackish water and in the blue clay.
Pl. [4], Figs. 1, 2, 4 and 6.
ACTINOPTYCHUS VULGARIS VAR. INTERRUPTA N. VAR.
Valve with fourteen sectors, the alternate ones divided by a smooth lanceolate space for about one-half the radius, forming with the smooth, circular umbilicus a seven pointed star. The sectors thus divided have coarser puncta in quincunx than the other sectors, ending in a smooth area near the margin, and also larger black puncta scattered from the centre to the semi-radius.
Near A. vulgaris var. neogradensis Pant.
Blue clay. Not common.
Pl. [4], Fig. 5.
ACTINOPTYCHUS HELIOPELTA GRUN. VAR.?
Valve circular, sectors, eight, umbilicus circular, without rays; border wide, cellular, with distinct rays. Inserted at a distance within the inner edge of the border are large processes, one on each of four alternate sectors, and two on each of the others. The sectors are cellulate and punctate.