VIII.—On Some Small Bivalve Shells from the Karoo Formation, South Africa

Abstract

Amongst the specimens sent many years ago, from South Africa, by the late Mr. Andrew Geddes Bain, to the Geological Society of London, are two small blocks of greenish-grey hard mudstone or shale, very slightly calcareons; one bed-plane in each, specimen bears upon its surface numerous valves of one or more forms of small Lamellibranchs, closely resembling the shells of the genera Cyrena and Cyclas in contour.