XXXIX] CTENIS 583 



Ctenis latifolia (Brongniart). 



This species 1 , originally referred to Taeniopteris, was trans- 

 ferred to Ctenis as the result of the discovery of anastomosing 

 veins in the type-specimen in the Oxford Museum. The segments 

 are shorter and broader than in C. sulcicaulis and very similar 

 to those of C. orovillensis Font. 



X 2 



\ 



FIG. 626. Ctenis sulcicaulis. (British Museum, V. 9012.) 



Ctenis sp. 



The pinna shown in fig. 624 from the Jurassic beds in York- 

 shire 2 is interesting as one of the few examples of the preservation 

 of the cuticular membrane. The straight or curved walls of 

 the epidermal cells agree with those of recent Cycads except 

 Stangeria, and each cell bears a large central papilla that gives 

 to the lamina the finely punctate appearance which has been 

 regarded as evidence of sporangia. The gaps in the cuticle 

 probably mark the position of sunken stomata. 



1 Seward (04) B. p. 115. 2 Ibid. (00) p. 21. 



