374 



STUDIES IN FOSSIL BOTANY 



by Brongniart as long ago as 1829 1 (see restoration, 

 in Frontispiece). 



It was suspected by Williamson, from the time of 



Fig. i^S. — Lyginodendron oldhamium. Radial section of stem, passing through the 

 base of a petiole, .v~, wood of >,tem, enclosing pith ; pc, pericyck- ; c, outer cortex ; 

 pet, petiole ; the vascular bundle extends from the petiole down into the pericycle of 

 the stem ; f, cortical spines. X 3^. Will, Coll. 1982. (G. T. G.) 



his first observations on the petioles of these leaves, 



1 The identity of the Lyginodcndroii foliage with this species of 

 Sphenopteris has recently been demonstrated in detail by Mr. Kidston in 

 his paper on the microsporangia of Pteridospermeae, cited below. 



