494 CYCADOPHYTA [CH. 



Dr Stopes says, indicates small leaf-bases, assuming that each leaf 

 received a single trace. In some respects the xylem and medul- 

 lary rays resemble those of Cycads, and the author of the genus 

 includes it in the Cycadophyta ; but as she points out there are 

 many pecuhar features, and it is clearly impossible to assign the 

 new type to a more precisely defined position. The possibility of 

 any purely mechanical explanation of the course of the tracheids 

 in the alternating zones is ruled out by the straight course of the 

 outgoing leaf-traces, and it would seem that the cambium must 

 have turned over at right-angles at regular intervals during the 

 growth of the stem. 



Cycadolepis. Saporta. 



This name was used by Saporta^ for linear-lanceolate scales 

 from Upper Jurassic rocks in France which "he compared with 

 bud-scales of recent Cycads. The imperfect scale described as 

 Cycadolepis villosa bears a striking resemblance to the hairy bracts 

 of Williamsonia and may well belong to that genus. Saporta's 

 term may be usefully employed in a more extended sense, including 

 not only lanceolate scales but larger and much broader scales 

 resembling the flattened petiole-bases on stems of Macrozamia, 

 Encephalartos, and some other recent genera, as well as detached 

 carpellary scales, other than Cycadospadix, and microsporophylls 

 which cannot be assigned to a particular stem. Two qualifying 

 subgeneric terms have been proposed^: 



i. Cycadolepis (Dory-Cycadolepis). Scales more or less linear- 

 lanceolate like those described by Saporta and a specimen from 

 Jurassic rocks of India named by FeistmanteP Cycadolepis 

 jnlosa. This type of Cycadolepis may be identical with the bracts 

 of Williamsonia flowers, though in the absence of any definite 

 evidence of such affinity the provisional generic name is more 

 appropriate. 



ii. Cycadolepis {Eury-Cycadolepis). Broadly oval or orbicular 



thick scales (figs. 582, 583), the broadest part being frequently 



nearer the distal than the proximal end. These larger scales 



though usually found as detached fossils have in one instance 



been obtained attached to an imperfectly preserved stem. 



1 Saporta (75) A. p. 200, PI. 114, figs. 4—6. = geward (95) A. p. 96. 



' Feistmantel (76^) PI. vii. fig. 5. 



