substance is soft, flaccid, and juicy, and the frond adheres very closely to 

 paper in drying. 



A very pretty and distinctly marked, thougli small species. 

 Our Figures 1 and 2, both of the natural size, and both full- 

 grown and in fruit, differ remarkably in luxuriance, but in no 

 other character ; and offer another instance, in addition to that 

 stated under Plate LIL, of the freer growth of Algae from Gar- 

 den Island, compared with those from Rottnest. Many more 

 instances might be given ; and I have been at a loss whether to 

 account for the increased development by the different position 

 of the two islands — which are only a few miles apart — or by the 

 difference of parasitism. The dwarf plants generally grow on 

 Zostera, the larger on some of the smaller Algae. Whether the 

 fact of growing on a flowering sea-plant has any influence on the 

 Alga is uncertain. If it have, one might infer that the root of 

 Algae was a more active organ than is commonly supposed. 



Fig. 1. Chondria Umbellula (from Garden Island). 2. The same (from 

 Rottnest) : — both of the natural size. Fig. 3. Apex of a ramulus, with con- 

 ceptacles. 4. Vertical section of a couceptacle. 5. A ramulus, with Mra- 

 spores. 6. Tetraspores : — the latter figures magnified. 



