Williamsonia Santalensis sp. nov. - A male fructification from the Rajmahal series, with remarks on the structure of Ontheanthus Polyandra Ganju

Abstract

W. santalensis sp. nov. is a male fructification from the Rajmahal series of the Upper Gondwanas. The material on which this species is based was discovered at Sakrigalighat in the Santal Parganas of Bihar. The fructification consists of a whorl of 20(?) microsporophylls coalescent towards the centre to form a shallow cup; the mode of attachment of the cup is not known. Each microsporophyll bears on its upper surface two rows of fingerlike appendages believed to be the spore-producing members. Inside each appendage there are two contiguous rows of small chambers. The spores are not preserved. The distal, sterile portion, of the microsporophyll shows an asymmetrical and obliquely twisted expansion of the lamina. The present discovery has thrown light on the structure of Ontheanthus polyandra Ganju, described as a unique type differing from the Bennettitales in several important features. A comparison of W. santalensis and O. polyandra shows that the two flowers had a similar plan of construction, and that the supposed differences from the Bennettitales seen in the latter are based on a mistaken conception of its morphology. W. santalensis and O. polyandra are kept separate for the present, but it is suggested that the discovery of more complete material in the future may make it possible to unite them under a common name.