thrice their diameter in length ; the endochrome, in the older portions of the 

 branch, occupies about one-third of the breadth. The involucres (of tetra- 

 spores) are usually borne on short, lateral, somewhat conical ramelli, con- 

 sisting of a single cell, nearly as broad as long, but sometimes a second cell 

 rises from the apex, by the side of the involucre. The tetraspores are 

 numerous in each involucre. Favellce not observed. The colour is a fine 

 crimson-lake, discharged in fresh-water. The substance is firm, somewhat 

 rigid when fresh ; soon becoming soft in the air, and when dry the plant 

 closely adheres to paper, and has a silky gloss. 



A very beautiful species when well grown ; and sufficiently 

 marked by its broadly flabellate, distichous habit, and the re- 

 curved or divaricating ramification. It must be admitted, how- 

 ever, as Professor J. Agardh remarks, that it is closely related to 

 the European G. seciindiflora ; and consequently to its southern 

 representative G. antarctica. Whether future observations will 

 not show that these three should be united, remains to be seen. 



Whilst collecting at Fremantle, I observed a marked difference 

 in size and luxuriance between the specimens of this plant found 

 at Garden Island and those from Rottnest. The first grew on 

 Alga, the latter on Zostera. Our fig. 1 is taken from one of 

 the former ; fig. 2, from one of the latter ; and these figures re- 

 present the average differences, which may perhaps be explained 

 by the difference of parasitism. The two islands are only a 

 few miles apart. 



Fig. 1 and 2. Griffithsia Binderiana, — the natural size. 3. Portion of a 

 branch, with involucres in situ. 4. An involucre, removed, and forced 

 open to show the enclosed tetraspores : — the latter figures magnified. 



