Published online by Cambridge University Press: 01 May 2009
Sp. char.—Tube small, sinistral, narrow, increasing but little in size towards the aperture, very narrow and fine towards the apex; volutions not in the same plane, somewhat raised, with a sunken apex, rather deeply umbilicated on the attached side; section circular. Surface marked with faint, regular, equidistant, transverse ridges, which are more marked along the union of the whorls (or “suture”) than on the periphery or back of the last volution.
page 304 note 1 M'Coy, Carb. Foss. Ireland, 1844, p. 169, t. 23, fig. 29.
page 305 note 1 Canad. Pal. Foss. i. p. 56.
page 305 note 2 P. 22, t. 2, f. 8.
page 305 note 3 Die Petrefactenkunde, etc., p. 96.
page 307 note 1 In specimens from other localities, however, the surface is quite as much Tinkled as in M'Coy's S. membranaceus.
page 307 note 2 Trans. Geol. Soc. Glasgow, iii. App. p. 23.Google Scholar