Note 19 — DIVISION III. PTERIDOPHYTA (VASCULAR CRYPTOGAMS).
Michael Cresse Potter translation
The position of the annulus varies in the different orders; longitudinal in Polypodiaceæ, Hymenophyllaceæ, and Cyatheaceæ; transverse in Schizæaceæ, Gleicheniaceæ; indistinct or apical in Osmundaceæ, Ophioglossaceæ, Marattiaceæ, Salviniaceæ, Marsiliaceæ.