pierced by a pore, through which the spores escape. The pericarp is very 

 thick, formed of the three strata of the frond, its cavity being hollowed out 

 in the middle of the medullary stratum. The tufts of spores are very nu- 

 merous, and spring from all parts of the walls of the conceptacle. Tetra- 

 spores are lodged in sori, under the tips of the segments of the frond, and 

 are much less common than the conceptacles. The colour is a dark brownish- 

 purple or dull-red, and becomes darker on drying. The substance is rigidly 

 membranous, and the plant does not adhere to paper in drying. 



I propose the present plant as the type of a new genus, related 

 to Chcetangium, but differing in having a distinct stem, emitting 

 branches that end in flabelliform fronds, traversed at base by a 

 vanishing rib ; and further, by the intermedial stratum of large 

 empty cells, and the more external conceptacles. The latter cha- 

 racters are of greater significance than the former, and suffice alone 

 to mark the genus. The little group of " Chatangiece " retained 

 by Professor Agardh as an Order, have so many characters in 

 common with Gelidiacece, that I am disposed to unite them (to- 

 gether with the Hj/pneacece) to that family. It appears to me 

 undesirable to multiply Families for every minor structural cha- 

 racter. The differences between the structure of the conceptacle 

 in CliCBtangia and Pterodadia are surely more generic than 

 ordinal. 



Hennedya crispa is abundantly thrown up at Rottnest Island, 

 after winter gales, and is then generally found well covered with 

 fruit. The specimens with conceptacular fruit are much the com- 

 monest. To the naked eye the plant strongly resembles a Thysa- 

 nocladia, particularly T. coriacea; but the ramification is different, 

 not to speak of fruit or structure. It is very apt to be infested 

 with small Zoophytes and Molluscoid Coralhnes {Bryozod), and 

 to the collector of these diversified and beautiful animalcule^ 

 its tufts will often afford a rich harvest. 



Fig. 1. A branch of Hennedya crispa, — the natural size. 2. Apex of a seg- 

 ment, with conceptacles under the tips. 3. Section through the frond, and 

 through a conceptacle. 4. Tuft of spores. 5. Section through a sorus; 

 tetraspores from the same : — the latter figures more or less magnified. 



