hi] SPOROGONITES 45 



among the Thallophyta rather than the Bryophyta. If the 

 sporangium were septate, the longitudinal septa might be 

 easily mistaken for a columella in material so imperfectly 

 petrified^. 



^ [These criticisms seemed justified at the time they were written, but 

 the discovery by Kidston and Lang of a Middle Devonian plant, Ilornea 

 Lignieri, in which the sporangium undoubtedly possesses a columella, puts 

 the whole question in a different light. The specimens of Hornea are 

 petrified and the whole organisation of the plant is shown; the eolumellate 

 sporangia are borne terminally on the dichotomous branches of a stem of 

 the Rhynia type. While Hornea and Sporogonites are evidently quite 

 distinct, there is now every reason to believe that Halle's interpretation 

 of the structure of his fossil was essentially correct ; the importance of his 

 discovery is manifest, whatever view may be taken of the affinities of the 

 plants in question. (See Kidston and Lang, On Old Red Sandstone Plants 

 showing Structure, from the Rhynie Chert Bed, Aberdeenshire. Part ii. 

 Additional Notes on Rhynia Gwynne-Vaughani, Kidston and Lang ; with 

 Descriptions of Rhynia major, n.sp., and Hornea Lignieri, n.g., n.sp. Trans. 

 Roy. Sac. Edinb. Vol. 52, Part in. 1920, p. 603.) D. H. Scott.] 



