114 



MEDULLOSEAE 



[CH. 



knowledge of the morphology of Medullosan sporophylls. Speci- 

 mens from the ironstone balls (Coal Measures) of Coseley near 

 Dudley showed seeds attached to portions of pinnae bearing 

 pinnules of Neuropteris heterophylla. The seeds are approximately 

 3 cm. long and from 1-10 to 140 cm. broad; oblong and gradually 



FIG. 422. Neuropterocarpus Kidstoni (Arber). (After Kidston; x 3.) 



tapering from the middle to a slightly curved and obtuse apical 

 snout (fig. 422). The outer surface shows numerous longitudinal 

 ribs which no doubt represent hypodermal fibres. The preservation 

 of the seeds, which appear to be circular in section, is not such 

 as to render possible a description of structural features. In their 

 asymmetrical form the seeds agree with the genus Platyspermum 

 as recently defined by Arber, but Kidston's specimens are in all 

 probability radiospermic. Kidston compares the Neuropteris seeds 



