PALEOBOTANY BEERY. 343 



The interstices of leaf bases were filled with, multicellular scales 

 (unicellular hairs in the Liassic G. Micromyela Moriere) correspond- 

 ing to the ramentum of ferns, in some cases (as in the genus Cyca- 

 della) very long and enclosing the whole trunk in a felt-like mass. 

 This ramental covering appears to have facilitated their subsequent 

 silicification, so that normally the fossil trunks show the ramental 

 areas as prominent partitions, separating the subrhombic angular 

 cavities left by the leaf stalks which decayed or were shed before 

 fossilization. Among the leaf bases occur numerous short axillary 

 branches each terminated by a solitary fructification or flower, as 

 Wieland terms the latter. The anatomy of the stem is much like 

 that of the cycads. There is a thick cortex, a comparatively thin 

 vascular cylinder and a very large pith containing secretory sacs 

 rather than gum canals. The vascular bundles are collateral, the 

 protoxylem is next the pith (endarch), and the few spiral marked 

 tracheids are soon replaced by scalariform tracheids which appear 

 to characterize the phylum, although pitted tracheids are recorded 

 in Cycadeoldea micromyela. In the leaves, however, the structure is 

 mesarch, suggesting their pteridophytic ancestry. The leaf traces 

 are single and direct and thus more simple in their arrangement than 

 in existing cycads. 



The axillary branches bear reduced leaves or bracts spirally ar- 

 ranged, and are of a length to bring the terminal flower at about 

 the general level formed by the persistent "leaf bases. The branch 

 axis expands into a subhemispherical or conical receptacle. At its 

 base and immediately beyond the enclosing bracts was inserted a 

 whorl of compound microsporophylls, united into a continuous 

 sheath proximad, expanding distad into a bipinnate frond with 

 alternate pinnae, all of which, except the apical and basal pairs, 

 bearing two rows of synangia, suggesting those of a marattiaceous 

 fern, the whole greatly resembling a fertile fern frond rather than 

 a verticil of stamens, and like the former circinate in vernation. 

 The surface of the receptacle above the staminate collar is beset with 

 slender pedicels, each bearing at its extremity a single orthotropoUs 

 seed, the interspaces packed w 7 ith sterile appendages known as inter- 

 seminal scales, which expand apically so that only the micropylar 

 part of the seed reaches the surface, and the wdiole is compact and 

 simulates a closed pericarp. Before proceeding with the descrip- 

 tion of the seeds, it may be well to state that of the various morpho- 

 logical homologies that have been advanced, that which regards the 

 interseminal scales as greatly reduced foliar appendages and the 

 seed-bearing pedicels as reduced megasporophylls seems the most 

 probable. 



The w y hole fruit-like body is ovoid or turbinate in shape, several 

 centimeters in length, the surface a mosaic of the expanded tips of 



