PTERIDOPHYTES 
163 
FIGS. 382-385. Aspidium: 382, general habit, showing leaves and circinate verna- 
tion, dorsiventral (subterranean) stem, and secondary roots; 383, a single pinnule, 
showing dichotomous veins and sori with shieldlike indusia; 384, section through a 
sorus, showing the indusium and long-stalked sporangia; 385, a single sporangium, 
showing the incomplete vertical annulus and the transverse dehiscence. After 
WOSSIDLO. 
