554 



CYCADOPHYTAJSr FRONDS 



[CH. 



with the axis. There is a close resemblance between this species 

 and Sphefiozamites Rogersianus Font.^: in the American type the 

 fronds must have been 1 met. long; the leaflets, 19 x 9 cm., 

 are elKptical, broadest near the apex and attached by the middle 

 of the rounded base. Between the divergent and forked veins 

 there is a fine granulation probably due to the presence of papiUae. 

 Pterophyllum Bronni and P. Rogersianum might be placed in 

 Schimper's genus Macrofterygium^, though another Raibl species, 

 originally described by Schenk as Pterophyllum giganteum^ and 

 referred by Schimper to Macropterygium, has much longer and 

 relatively narrow pinnae and agrees more closely with Ptero- 

 phyllum as the genus is usually defined. In order to emphasise 

 the distinctive features of Pterophyllum Bronni and Fontaine's 

 Virginian species they may con- 

 veniently be spoken of as Ptero- 

 phyllum {Macropterygium) Bronni 

 and Pterophyllum (Macropterygium) 

 Rogersianum. 



Pterophyllum Braunianum Goeppert. 

 In this Rhaetic species* (fig. 613) 

 the narrow hnear pinnae, contiguous 

 or more or less distant, are 1 — 2 mm. 

 broad and may exceed 5 cm. in length 

 though they are usually shorter ; 

 they are attached more or less at 

 right-angles to the sides of a trans- 

 versely wrinkled rachis. The base 

 of the lamina is broadened and the 

 veins are parallel, simple or forked. 

 The epidermal cells have sinuous 

 walls. 



Fig. 613. Pterophyllum 

 num. (A, nat. size ; B, 

 after Schenk. ) 





Braunia. 

 enlarged ; 



Pterophyllum Tietzei Schenk. 



A Rhaetic species founded^ on specimens from Persia and 

 described also by Zeiller® from Tonkin represented by fronds 



1 Fontaine (83) B. p. 80, Pis XLin.— v. 2 Schimper (72) A. pp. 127, -132. 



' Schenk (67) PI. 11. * Goeppert (44); Schenk (67) A. p. 164, PI. xxxvin. 



6 Schenk (87) B. p. 6, Pis. vi., ix. 



« Zeiller (03) B. p. 189, PI. xlvii. eg. 1. 



