CUTICLES OF CYCADEAIV FEONDS. 



167 



ill the cells of the nerve-courses. The cell-walls, particularly in (7. mexicanay are very 

 strongly layered (PI. 18. figs. 1-4). Ceratozamia has vi^ide stomatal regions and narrow 

 nerve-courses, the demarcation of the areas heing most distinct in C latifolia. The 

 stomata lie parallel to the pinna-axis, or somewhat obliquely to it, and are sunk below 

 the level of the epidermis, having one intercalated series of cells (PI. 18. fig. 4). The 

 air-space is lined with a layer of cutin, extending as is usual to the ventral walls of the 

 guard-cells, and its somewhat oval opening is surrounded by from four to six subsidiary 

 cells ; five were observed in C. latifolia (text-fig. 12), six in C. mexicana (PI. 18. fig. 2), 



Fig. 11 



Fig. 12. 



tozamia latifolia.— Vi^^ei cuticle in surface view, 

 showing thin-walled and thick-walled cells. At 

 *, an elongated cell is divided by a septum. 

 X450. 



C. latifol 



Lower cuticle (after maceration) in surface 

 view, showing a stoma-opening (s) surrounded by 

 five subsidiary cells (p and 0- X 450. 



and usually four in C.fusco-viridis 



Kraus notes four in C. Kmteriana. The subsidiary 



cells do not overarch the air-space to any extent 



The cuti 



layer is throughout fairly thick, particularly on the upper surface of the 



leaves (PL 18. figs. 3 & 



Macrozamia, Miq 



PI. 18. figs. 14 & 15 ; text-figs. 13-18 



D 



References : — Bornemann 



44 



(1881) 



Nestler (1895), pp. 352, 354; Taf. 12. figs. 10, 11 ; Taf. 13. fig. 16. 



Species examined : — M. spiralis ( 



Miq.?); M. corallipes, Hook, f.; M. Denisonii, F. Muell 



M. Hopei, T. Hill ; ^f. cylindrica, C. Moore ; M. Macleayi, M 



n 



