short ramuli, both along the denuded portion and along the rachis of the 

 pinnated part, these ramuli being simple or pinnate, squarrose, and very 

 irregular in ramiticatiou and insertion. Pinna; 3-3 inches long, the lowest 

 longest, ^ line in width, eompressed, once, twice, or thrice pinnulated. 

 Pinnules opposite, very close together, subulate, acute, some simple, some 

 again pinnulated in their upper half. Conceplacles 2-3 together, near the 

 tips of the ultimate pinnules, containing a very dense nucleus. The colour 

 is a very dark brownish-red, becoming much darker and browner in drying. 

 Substance coriaceous and very tough. In drying the frond does not adhere 

 to paper. 



In structure of frond and in general habit, the genus Th^- 

 sanodadia (and especially the species here figured) agrees well 

 with Gelidium and its allies ; but in the structure of the cysto- 

 carp, — though this too seems in an intermediate condition, — the 

 preponderance of character is in favour of Spharococcoidecs, 

 where it is placed by Agardh. I formerly erroneously referred 

 it to LaurenciacedB. 



Founded on the Bhodomela ? dorsifera of Agardh, Thysano- 

 cladia now includes several species, all natives of Australia ex- 

 cept one, which is found under the ledges of coral-reefs in the 

 Pacific. All are deep-water plants and of a peculiarly rigid 

 texture, brightly coloured when growing, but invariably darken- 

 ing or even blackening in drying. 



Kg. 1. Thysanocladia oppositi folia, — the natural size. 2. A pinnated 

 ramulus {plumule). 3. Cross section of the frond. 4. Cross section of 

 fertile ramulus and conceptacle. 5. Spore-strings : — magnified. 



