XXXIX] PSEUDOCTENIS 585 



may be almost parallel to the rachis. The longest pinna recorded 

 is 17 cm. and the lamina tapers to a slender apex; the veins are 

 parallel and occasionally forked, but cross-connexions are rare. 

 The partially petrified rachis of one specimen showed hypo- 

 dermal stereome and some secretory canals as in recent Cycads. 

 The specimen from Wealden rocks near Hastings (fig. 627), 

 originally described as Zamites sp. 1 , is probably specifically 

 identical with Pseudoctenis eathiensis. The South African Wealden 

 species, originally described by Tate as Palaeozamia Rubidgei 2 , 

 agrees closely with Pseudoctenis and is probably an example of 

 that genus. This type bears a close resemblance in the form 

 of the frond to Ctenophyllum grandifolium Font. 3 and C. Wardi* 

 Font, from American Trias and Jurassic rocks respectively. 

 Pseudoctenis crassinervis Sew. 5 is another Scotch form with coarser 

 veins. 



A frond very similar in habit to P. eathiensis is represented 

 by Pseudoctenis ensiformis Halle 6 from the Jurassic strata of 

 Graham Land originally referred by Nathorst to Pterophyllum. 

 An examination of the type-specimen in the Stockholm Museum 

 revealed its resemblance to the Scotch species P. eathiensis: 

 a single anastomosis was noticed in one of the pinnae. The 

 broadly ensiform obtuse pinnae, reaching a length of 7 cm. with 

 a maximum breadth of 3 cm. at their expanded bases, vary in 

 breadth and are attached at right-angles to a slender rachis. 

 The veins, 1 1-5 mm. apart, are parallel and strong. The varying 

 breadth of the pinnae irrespective of their position on the rachis 

 is a distinctive feature. Halle draws attention to a resemblance 

 of this Antarctic species to Ctenophyllum latifolium Font, a Potomac 

 type referred by Berry 7 to the genus Ctenopsis on the rather slender 

 ground that the veins are arranged in pairs. Berry in a footnote 

 expresses the opinion that Ctenopsis is very closely related to or 

 possibly identical with Pseudoctenis. 



If the bases of the pinnae in the specimen of P. ensiformis 

 figured by Halle are complete, as they appear to be, the frond 



1 Seward (95) A. p. 89, fig. 5. 



2 Tate (67) PL v. fig. 3; Seward (03) B. PI. v. fig. 3. 



3 Fontaine (83) B. Pis. xxxix. XLII. 4 Fontaine in Ward (05) B. PI. xxm. 

 5 Seward (II 2 ) Pis. iv., vn. 6 Halle (13 2 ) p. 51, PI. vi. fig 8. 



7 Berry (11) p. 349. 



