Pyrgo williamsoni (Silvestri, 1923)

Figure 20.8

1923 Biloculina williamsoni Silvestri, p. 73.

2003 Pyrgo williamsoni (Silvestri); Murray, p. 17, pl. 4, figs. 7-8.

2010 Pyrgo williamsoni (Silvestri); Margreth, p. 103, pl. 9, fig. 6a-c.

Description. Test ovate, elongate, tapering at the apertural end, aboral end broad, wall porcelaneous, imperforate, surface smooth; chambers added obliquely, biloculine chamber arrangement, coiling involute, periphery subacutely rounded, sutures distinct, slightly depressed; aperture elliptical, with a simple bifid tooth.