null fow lateral processes or with none; sometimes it is digitate; and some- 

 times, after one or two tbrkint>'s of tlie main segment, the general ramifica- 

 tion is irrcgnlarly piiuiate. Usually the margin emits lateral, leaf-like seg- 

 ments or pinnae, which commence as short ami blunt lobules, and gradually 

 increase till they arc ^-l inch long, and }-w inch wide, becoming oblong, 

 oval, or obovate. All tlic apices are blunt, and the margin is flat, not 

 curled. Cydocarps irregularly scattered over the whole surface, prominent, 

 dark-coloured. Tetraspores dispersed through the surface-cells of the leaf- 

 lets, on diflerent plants. Colour a delicate rosy-red, becoming darker in 

 drying, and sometimes changing to brownish-red. Substance softly mem- 

 branous, but not gelatinous. In drying, the frond shrinks and adheres 

 pretty closely to paper. 



In a recent number (Plate CXCIX) I figured a doubtful 

 member of the genus BjhodophyUis ; the plant now given may 

 be taken as a typical representative. The structure of the cys- 

 tocarp, when nearly ripe, in all genuine species of the genus, 

 is remarkable, and a vertical section (Fig. 3) is a beautiful mi- 

 croscopic object, from the strings of ruby-like cells lying in a 

 matrix of clear gelatine, through which an irregular dehiscence 

 takes place eventually. The tetraspores are generally of large 

 size, lying apart, and their zoned character is readily seen, even 

 without dissection. 



In most species of RJiodophyllis, the cystocarps are marginal ; 

 here they are scattered irregularly over the surface, by which cha- 

 racter this plant may alw^s be known from the smaller forms of 

 R. memhra?iacea, some of which resemble it in ramification. 



Fig. 1. Rhodophyllis volans. 3 Another specimen, in fruit: — both of the 

 natural size. 3. Section tlirough a conceptacle. 4. Section of the frond. 

 5. Portion of the surface of the frond, with scattered tetraspores. 6. Some 

 tetraspores, removed : — magnified. 



