On Dayia navicula (J. de C. Sowerby) and Whitfieldella canalis (J. de C. Sowerby) from the English Silurian

Abstract

During 1931–4 several hundred specimens of these two species were collected, including a quantity of excellently preserved silicified material from an exposure of the Dayia Shales (Elles and Slater, 1906, pp. 197 and 198), near Norton in Shropshire. Serial sections and development of the material have made possible the detailed descriptions which follow.