TO THE KNOWLEDGE OE PLATYZOMA MICROPHYLLUM. 
165 
DESCRIPTION OF FIGURES IN THE TEXT. 
Fig. 1. Diagram of a fertile pinna of Platyzoma seen from below. The margins are very revolute. The 
sporangia are of variable size, but are invariably inserted terminally upon the main lateral veins or upon 
branches of these. x 10. 
Fig. 2. Transverse section of the revolute margin of a fertile pinna of Platyzoma. x 36. 
Fig. 3. Stoma from the under surface of a fertile pinna of Platyzoma, and with starch grains in the 
surrounding epidermal cells. x 36. 
Figs. 4, 5, 6. Various views of a small sporangium of Platyzoma. x 36. Figs. 4 and 5 show the sizes 
of the small and intermediate spores relative to the sporangia. 
Fig. 7. A small sporangium opened. It shows the three-rowed stalk, and the least irregular annulus 
. observed, x 36. 
Figs. 8, 9. A back and a front view of a largo sporangium of Platyzoma. Fig. 8 shows the size of a 
large spore relative to the sporangium, x 36. 
Figs. 10, 11. Two large sporangia opened. These show the variation in the construction of the stalk, 
and the conspicuous irregularities in the annulus. x 36. 
Fig. 12. A spore of the smallest size, x 60. 
Fig. 13. A spore of the intermediate size. x 60. 
Fig. 14. A spore of the largest size. x 60. 
Fig. 15. Spore-markings on the convex surface of each spore- type. x 90. 
Fig. 16. Spore-markings on the flat triangular faces of each spore-type. x 90. 
Fig. 17. Transverse section of a large spore of Platyzoma. x 60. 
The author is indebted to the Carnegie Trust for their assistance in the illustration of this paper. 
26 
TRANS. ROY. SOC. EDIN., VOL. LII, PART I (NO. 7). 
