IX 



FILICINEJE LEPTOSPORANGIAT2E 



313 



FIG. i73.Onoclea struthiopteris. A, B, Germinating spores with the perinium re- 

 moved, Xsoo; C, young prothallium, Xioo; D, E, older prothallia with two-sided 

 apical cell (x), X3oo; F, small female prothallium seen from below, X2$; G, 

 very young prothallium with the two outer spore-coats, X3oo; r, primary rhizoid; 

 ar, archegonia; p, perinium; ex, exospore. 



