63 



humble way a sort of affinity with the monosiphonous genus Apjohnia, especially when the 

 latter is seen neatly arranged and flattened in the herbarium. But Apjohnia possesses in the 

 basal transverse annular corrugations of its articuli a Valoniaceous character, of which we find 

 no tracé in Rhipidodesmis and Callipsygma. 



The distribution of this species is, so far as is known, confined to the Indian Ocean. 



8. Callipsygma J. G. Agardh. 

 (Fig. 144—146). 



J. G. Agardh Till Alg. Syst. V. 1887. p. 65 ; De Toni Syll. Alg. I. 1S89. p. 504; Wille in Engler 

 und Prantl natürl. Pflnzenfam. I. Teil, 2. Abteil. 1890. p. 142; also Nachtrage 1910. p. 128. 



Frond uncalcified, green, complanate, sparingly branched ; branches 2.5 — 3. o cm. long. 



Stipes compressed, dark coloured, almost concealed by a covering of short appressed, 

 flexuose, dichotomously branched, moniliform, green filaments, 100 a thick. 



Stipes and branches emitting laterally from their edges longer, patent, complanately 

 dichotomously divided, green, more sparsely constricted filaments, 5 mm. long, forming a con- 

 tinuous fringe along the edge of the stem and branches, and giving them a zonate plumose 

 appearance. Fringing filaments repeatedly dichotomously divided, evenly constricted at the 

 dichotomies; pseudo-articuli 225 — 270 u. in diam., 1.5 — 2.0 mm. long below, shorter above 

 (0.75 — 1.0 mm.), free but laterally contiguous and arranged almost entirely into narrow, 

 apparently monostromatic flabellules (or into fascicles?). [It is unknown whether the successive 

 dichotomies are in alternate planes or in the same plane]. 



1. Callipsygma Wilsoni J. G. Ag. loc. cit. 



Syn. Callipsygma Wilsoni A. & E. S. Gepp in Journal of Botany XLIII. (1904) p. 364 — 366, 

 tab. 467, figs. 5 — 7. 



Hab. INDIC. Australia, Victoria, Port Phillip Heads, Sorrento, 1884, J. Bracebridge Wilsoni 



Characters as in genus [Figs. 144 — 146]. 



The systematic position of this genus has yet to be" finally determined. J. G. Agardh 

 (loc. cit.) compared it with an imaginary Rhipoccphalus, having all its parts flattened into the 

 same plane, in consquence of which fanciful view De Toni (Syll. Alg. I. 1889, p. 504) and Wille 

 (in Engler & Prantl's Die natürl. Pflanzenfamilien. I. 2. p. 142 1890) were led to place the 

 genus between Rliipocephaliis and Udotca. The only species of Rhipocep/iahis which Agardh 

 knew was R. Plioenix ; and that species consists of a well-developed and thickly calcified 

 terete stipes bearing a head or cone composed of a series of verticillately arranged small, 

 cuneate flabellules, which are often laterally coherent and always calcified, and which consist 

 of a row of contiguous juxtaposed filaments cemented together laterally in one plane. 



Callipsygma, as described above, has a very different structure (fig. 144), its green, 

 uncalcified flabellules (fig. 145) being in size and character almost exactly like those of individual 

 plants of Rhipidodesmis cacspitosa (fig. 141), to which species it is in our opinion most closely 



