I.—Sphærostoma ovale (Conostoma ovale et intermedium, Williamson), a Lower Carboniferous Ovule from Pettycur, Fifeshire, Scotland

Abstract

The Palæozoic ovule, to which the generic name “Sphærostoma” is now given, was originally described by Williamson in 1877 under the names Conostoma ovale and Conostoma intermedium . He referred sections of different individuals to different species owing to the imperfect condition of the material then available, but expressed the view that Conostoma intermedium “may possibly be a state of Conostoma ovale .” The new material has rendered this interpretation a certainty. With respect to the reference of this ovule to the genus Conostoma , Williamson again expresses some hesitation, merely stating that “it appears to be of the same generic type.” The genus Conostoma was established for an Upper Carboniferous ovule which Williamson designated Conostoma oblongum .