plant well agrees with most of the Gelidiacea : but if the cysio- 

 carps above described be normal, and fully developed, they 

 scarcely exhibit the cystocarpic structure proper to that family, 

 and rather indicate an affinity with Rlwdijmeniacece. I have only 

 seen fruit on a small fragment, communicated by my friend 

 Sonder, and none of the cystocarps cut through by me appeared 

 to be fully organized. 



In its mode of branching, colour, and substance, Nizymenia 

 aiistralis so closely resembles Areschouyia conferta, figured in 

 our next Plate, that I formerly took it for a broad variety of that 

 Alga, and distributed specimens of it as such. 



Fig. 1. Nizymenia atjstralis, — the natural size. 2. Part of a small branch, with 

 conceptacles. 3. Vertical section of a conceptacle. 4. Transverse section 

 of the frond: — the latter figures variously magnified. 



