(.1 NTS 1'AI !..\\ ICINIA 



fronds arc about 2.5 cm. in width (Fig. 5). In the male plants they are 

 somewhat smaller. The apex of each segment is indented, and the mar 

 gin is wavy, with conspicuous teeth, or narrow lobes, which are usually 

 pointed and hooked (Fig. 4, A). 



T 

 A 



* .SL. ** ~~\ TT r~Ti . i| 



Fig. 6. Paltavicinia 



A. Median section of an archegonial receptacle ; in, involucre ; per, perianth. 



B. A nearly mature archegonium. 



C. D. Ventral part of two old archegonia. 



E. Receptacle containing an embryo; cal. calyptra. 



F. Transverse section of a similar receptacle. 



G. H. Archegonial receptacles. 



