XXXVI] 



CYCADEOIDEA 



399 



consisting of the radially elongated cells (figs. 524, 525, ar ; 527, c). 

 The superficial layer assumes a different aspect in the micropylar 

 region, its cells being thicker walled, as are also those of the sub- 

 epidermal layer (fig. 524, A and B). The micropylar canal 



cm. 



-at 



FIG. 525. Cycadeoidea (Bennetf.ites) Morierei. Section of a seed and adjacent inter- 

 seminal scales, tm, micropylar tube ; n, nucellar beak in the micropylar canal, 

 cm; cp, pollen-chamber; co, archegonia (?); em, position of the embryo; 

 ch, chalaza ; dn, remains of the nucellus ; af, fibrous layer passing below into the 

 shell, eg, and the peduncle, Tf; tch, fleshy layer; ar, radial and tubular layers 

 represented in the peduncle by the tubular envelope at; EC, swollen ends of 

 the interseminal scales. (From a drawing kindly supplied by Prof. Lignier; 

 x 10.) 



(figs. 524, 525, cm) is cylindrical in the lower part but at the 

 apex is reduced to a long and narrow slit bounded by an 

 internal epidermis of radially stretched cells which in the lower 

 portion of the tube are thinner walled and isodiametric. The 

 rest of the testa is differentiated into two regions; an outer 



