i82 SCIENCE PROGRESS. 



following the course of the veins on the under surface of the 

 lamina, such a frond imperfectly preserved as an impression 

 would probably convey the idea of fairly broad veins rather 

 than of rows of sporangia. The genera Acrostichiiui., 

 Hemionitis and others afford close parallels with Glossop- 

 teris as regards shape and venation. 



Another well-known fossil often associated with Glossop- 

 teris is the genus Vertebraria, founded by Royle in 1829.^ 

 He proposed this name for some Indian fossils which are 

 figured in his work on the Natural History of the Himala- 

 yas, and described the specimens under two specific names, 

 V. indica and V. radiata. No real specific difference can 

 be detected in the examples figured. Bunbury, Feist- 

 mantel and other writers have given more complete de- 

 scriptions of this genus ; a typical specimen usually presents 

 the appearance of a long cylindrical structure varying in 

 breadth from a quarter of an inch to an inch, occasionally 

 branched, and the axis marked by a median line from which 

 offshoots pass off at intervals to the margin of the fossil. 



Bunbury was the first to suggest that the Vertebraria 

 might be the roots of some large plant." The specimen on 

 which Bunbury's opinion was based is in the Museum of 

 the Geological Society ; it shows the numerous roots re- 

 markably well and the figure hardly does justice to this 

 unusually interesting example of the genus. '^ Until quite 

 recently we have been absolutely in the dark as to the 

 nature and relationship of this fossil. Zeiller^ has now 

 brought forward good evidence that Vertebraria is the 

 rhizome of Glossopteris. From an examination of speci- 

 mens recently found in the Beaufort beds of South Africa 

 he has been able to trace a connection between Glossopte7ds 

 and Vertebraria ; he finds that the median veins of the 

 former are continued as transverse grooves in the axis ot the 

 latter. The median line occupying the axis of a Vertebraria 

 would thus be the central stele and the lateral offshoots leaf- 



^ Royle, p. xxix.*, pi. ii. 



2 Bunbury. The specimen figured by Bunbury (pi. xi., fig. 3), now in 

 the Geological Society's Museum, shows the roots remarkably well. 

 '■' Bunbury, pi. xi., fig. 3. ■* Zeiller (5). 



