POLYSTOMELLA FABA. 349 



elongations of the sarcode cavity of the segment ; septa narrow and limbate in the 

 more advanced forms ; septal apertures numerous, at or near the edge of the 

 segment in contact with the edge of the previous whorl. Supplemental skeleton 

 present ; septal bridges and canal-system more or less fully developed ; canals 

 opening at the umbilicus, and by pores along the sutures. Aperture a A-shaped 

 line of perforations at the base of the septal face of the last chamber. 



1. Poltstomella faba (Fichtel and Moll), 1798. "Woodcuts, figs. 30 a, b. 

 Part I, 1866, Appendix I, Table No. 99 ; Appendix II, Table No. 98. 



Nautilus faba, Fichtel and Moll, 1798. Testae. Microscop., p. 103, pi. xix, 



figs, a — c. 

 Chrysolus (Chbtsole peble), Montfort, 1808. Conch. System., vol. i, p. 26, 



No. 7. 

 Poltstomella faba, P. and J., 1860. Ann. Mag. N. H., ser. 3, vol. vi, pp. 102, 



103, No. 5 ; and ibid., p. 339, No. 5. 

 Poltstomella ceispa, var. (Nonionina) eaba, Parker and Jones, 1865. Phil. 



Trans., vol. civ, p. 402, pi. xiv, fig. 36. 



Characters. — Nautiloid, somewhat elongate and compressed ; chambers 

 numerous, arcuate ; sutures more or less distinctly pitted ; aperture crescentic, 

 often barred. This form, by its sutural pittings and its foraminate aperture, 

 has passed from Nonionina into Polystomella. 



Figs. 30 a, 30 b.— Polystomella faba (Fichtel and Moll). From the 'Philos. Trans.,' 

 vol. civ, pi. xiv, figs. 36 a, b. x 12 diameters. 



Occurrence. — Polystomella faba (usually referred to as a Nonionina) is known 

 from the Arctic seas, and from the Adriatic. It occurs fossil in the newer 

 Tertiaries of Italy (Tuscany). 



The specimens formerly in S. V. Wood's Collection, and referred to in Part I, 

 Appendices I and II, have been lost sight of. It is stated (in Appendix II) as 

 having been rather common in the Coralline Crag at Sutton, and very rare in the 

 Red Crag. 



