The Geological History of Plants

by Sir John William Dawson

Fig. 54.—Sphenopteris latior, Dawson. Coal-formation, a, Pinnule magnified, with traces of fructification.

Fig. 55.—Fructification of Palæozoic ferns, a, Thecæ of Archæopteris (Erian). b, Theca of Senftenbergia (Carboniferous). c, Thecæ of Asterotheca (Carboniferous).