XXl] 



OSMUNDACEAK 



335 



the row.s of superposed short cells have probably been produced 

 by the transverse septation of cells which began by elongating 

 as if to form conducting tubes and ended by assuming the form 

 of vertical series of parenchymatous elements. 



In another Jurassic species, Osmundites Gibbiana^, the xylem 

 is of the Osniunda type and consists of about 20 strands instead 

 of a continuous or almost continuous cylinder. 



Osmundites Kolhei Seward, figs. 253 — 255. 



This species was founded' on a specimen obtained by Mr 

 Kolbe from the Uitenhage series of Cape Colony^. The fossil 



Fig. 254. Osviundites Kolhei. (Leaf-scars.) 



flora and fauna of this series point to its correlation with the 

 Wealden or Neocomian strata of Europe-^. The type-specimen 

 consists of several pieces of a stem (fig. 253) which reached 

 a length of about 90 cm. On the weathered surface the 

 remains ot petiole-bases are clearly seen and on the reverse 

 side of the smaller piece shown in the figure numerous sinuous 

 roots are present in association with the leaf-stalks. The 

 depression c in the larger specimen may mark the position 

 of a branch: at a fig. 253 (enlarged in fig. 254, a) the 

 vascular strand of a petiole is exposed as a broad U-shaped 

 band and at 6 (fig. 254, b) the form of the petiole-bases 

 is clearly shown^ With the stem were found imperfectly 

 preserved impressions of fronds referred to Cladophlebis denti- 



1 Kidaton and ttwynne-Vaughan (07). 

 •■i Seward (07-') p. 482, Pis. xx. xxi. 

 ■• Seward (03) ; Kitchin (08). 

 ■» Cf. Todea Wilkesiana (p. 28G). 



