To the European botanist the Plate here given will recall to 

 mind the common Fucus serratas of the Northern Atlantic, 

 which has a frond of very similar form and similarly serrated. 

 In the northern species, however, as in all of the restricted 

 genus Fucus, the spore- cavities are confined to the apices of the 

 branches, which are transformed into imperfectly organized recep- 

 tacles; but in this " representative form " of the Southern Ocean 

 the spore-cavities are scattered, without order, over the whole 

 frond. On this character Decaisne founded his genus Myrio- 

 desma, which now includes at least three species, two from 

 Western Australia and one from Victoria and Tasmania. The 

 latter [M. integrifolia, Harv.) having been figured in the ' Flora 

 Tasmanica ' will not be re-figured in the present work. It may 

 be thus characterized : — 



M. integrifolia; caitle bad tereti sursum plus minus alato, costa evanescente ; 

 phyllodiis distichis decomposite pinnali/ldis, laciniis enervibus linearibus obtusis 

 margine subintegerrimis (v. apicem versus denticulalisj ; scaphidiis numerosissimis 

 sparsis. 



Halo. Geelong and Western Port Victoria ; and Tasmania. 



A fourth supposed species {M. quercifolia, Ag.), founded on 

 the " Lessonia quercifolia, Bory," a little-known plant, said to 

 be a native of New Zealand, requires re-examination and veri- 

 fication. 



Fig. 1. Myriodesma latifolia ; a leaf, — the natural size. 2. Section of the 

 frond, through the centre of one of the spore-cavities. 3. Spores. 4. A 

 tuft of antheridia .- — the latter figures more or less magnified. 



