On the structure and relationships of Trigonocarpus shorensis, sp. nov. : a new seed from the Palaeozoic rocks.

Abstract

The bulk of the material which forms the basis of this communication was placed in the writer's hands for investigation by Prof. P. W. Oliver. And I gladly take this opportunity of expressing my deep indebtedness to him for much helpful advice and criticism and also for putting at my disposal for examination such slides of the University College Collection as I have had occasion to consult. My thanks are also due to Dr. D. H. Scott and to Prof. F. E. Wells for the loan of preparations of this seed. To Dr. Scott I am also indebted for permitting me to examine the more important sections in his unique collection of Trigonooarpus Parkinsoni, without which an adequate comparison between the two seeds would not have been possible. A full description of the new seed is embodied in the following pages together with a consideration of its relationships and the theoretical questions to which its structure gives rise. In the former connection the organisation of Trigonocarpus Oliveri is reconsidered and good reasons are shown for its exclusion from that genus. The same methods have been employed in the reconstruction of the present seed as were used in the investigation of Conostoma oblongum and C. anglo-germanicum. These have been recently described by the writer and need not be recapitulated here. In order to facilitate reference the same general plan of arrangement has been adopted as has been employed in other recent papers dealing with fossil seeds.