14 



CYCADALES 



[CH. 



species Cycadites Saportae, and it is noteworthy that narrow leaflets with a 

 strongly revolute lamina would produce casts with two parallel ribs (the 

 grooves between the midrib and the edge of the lamina) simulating the double 

 midrib of the fossil genus Pseudocycas. In some fronds, e.g. C. Cairnsiana, 

 the midrib is hardly visible on the upper face of a dried pinna which shows a 

 longitudinal wrinkling simulating parallel venation. 



FIG. 385. A, B, Cycas Micholit^ii. (After Thiselton-Dyer. ) C, Zamia angustifolia. 



Encephalartos. The fronds of this genus, in Encephalartos Laurentianus 1 

 reaching the exceptional length of 7 metres, bear alternate pinnae exhibiting 

 a considerable range in form and breadth. In E. longifolius, E. Altensteinii 

 (fig. 386, C), E. Lehmanni, etc., the pinnae are for the most part linear, reaching 

 a length of 20 cm. and a breadth of 2 cm. : in E. coffer (fig. 387, D), E. latifolius, 

 and others the pinnae are broader and shorter and often spinous. A frond of 

 E. longifolius or E. Altensteinii may bear both entire and lobed, spinous 

 pinnae. In E. Frederici-Guilielmi (fig. 387, G) and E. GheUinckii 2 (fig. 382) 

 the pinnae are very narrow and almost filiform, with revolute edges. The 

 thick and leathery pinnae of some species are attached obliquely to the edge or 



1 Gard. Chron. 1904, June 11, p. 370. 



Seward (97). 



