564 



CYCADOPHYTAN FRONDS 



[CH. 



observations as regards the stomata, but he shows that there is 

 no evidence of the existence of a midrib in the strict sense, the 

 appearance of a single or double median vein being due to the 

 presence of a dorsal stomatiferous groove, the edges of which would 

 produce an impression on the matrix of a double vein or, if the 



Fie. 618. 



Pseudocycas Saportae. From the Wealden, near Hastings. 

 (British Museum, V. 2777; ^ nat. size.) 



groove became narrower, the impression would suggest a single 

 midrib. 



Pseudocycas Roemeri (Schenk). 



This Wealden species recorded from North Germany^ and 

 the Sussex coast^ has broader pinnae laterally attached to the 



1 Schenk (71) B. PI. xxxii. fig. 1. = Seward (95) A. pp. 2—7. 



