margin, and ending in the marginal indentations. The apices are blunt. 

 The margin is more or less evidently serrulate, never quite entire, but often 

 with obsolete and subdistant toothing. The surface-cellules are very mi- 

 nute. Ceramidla oblong-ovate, wide-mouthed, ending in short pinnules ; 

 spores large, pedicellate, with distinctly granular endochrome. Sorl form- 

 ing long or short lines within the margin of the larger and lesser laciniae. 

 Colour a clear rose-red. Substance delicately membranous, but not very 

 soft. In drying the plant adheres, but not very firmly, to paper. 



In 'Nereis Australis' the present plant is erroneously referred 

 to JDictymenia, as it was formerly, with equal impropriety, re- 

 ferred to Delesseria. Both references were made in ignorance 

 of the fructification, which, being now discovered, guides us to 

 its true affinities. These are with two New Zealand Algae, one 

 of them figured in Ner. Austr. (t. 33), the other in M. N. Zeal, 

 (t. 113), and both agreeing with the present Alga in general 

 aspect and in fructification, but being less membranous, with 

 thicker intermediate stratum, and wanting the midrib and 

 nerves. Our present plant, therefore, while it may fairly be 

 placed in Cladhymenia, will form a subtype in that genus, 

 characterized by the presence of midrib and nerves. 



Fig. 1. Cladhymenia conferta, — the natural size. 3. Apex of a lacinia, bear- 

 ing ceramidla. 3. Spores. 4. Apex, bearing iiitramarginal sori. 5. Te- 

 traspores. 6. Fragment of the frond, to show the superficial cellules: — 

 variously magnified. 



