Abstract
In a note communicated to the Royal Society in May, 1903, it was stated that a re-examination of the Palæozoic seeds, placed by Williamson in his genus Lagenostoma , had revealed unexpected points of agreement between the structure of the envelopes of certain of these seeds on the one hand and that of the vegetative organs of Lyginodendronon the other, and the conclusion was drawn that the seed Lagenosloma Lomaxicould have belonged to no other plant than Lyginodendron . In the present paper it is proposed to give a full statement of the evidence upon which that conclusion is based, to describe the seed in detail, and to consider the bearing of the discovery upon the question of the relations of the Ferns and Gymnosperms.