XIII.—On the Structure of Deltasperma fouldenense gen. et sp. nov., and Camptosperma berniciense gen. et sp. nov., petrified seeds from the Calciferous Sandstone Series of Berwickshire

Abstract

Two new species of fossil seeds are described from the Cementstone Group of Berwickshire. Deltasperma fouldenense is asymmetrically platyspermic, and has large superficial cells chiefly on the more convex side. It is orthotropous but shows no pedicel. Camptosperma berniciense is campylotropous and has a dense integument. A vascular bundle to the chalaza ends at the nucellus base. Both seeds possess a similar lagenostome and short salpinx; two integumental bundles which expand in the free lobes; a female prothallus with a wide “tent-pole” and about two archegonia; a nucellus adnate to the integument below the lagenostome; and spherical pollen grains in the pollen chamber. The seeds show most affinity with the Lagenostomales.