IX. ALGjE. 
643 
c. Placenta axial or parietal, or suspended by filaments in the cavity of the external or 
half-immersed conceptacles. 
Tribe V. Gelidiese. Frond inarticulate, cartilaginous or horny, opaque, the axis ( at 
least ) formed of elongate confervoid filaments (axis articulate in Caulacanthus when 
young). 
* Conceptacles 'Z-cetled 61. Gelidium. 
** Conceptacles \-celled, traversed by filaments, hemispherical, or, if immersed, in 
swollen branchlets ( unknown in Caulacanthus). 
Frond subtubular ; axis articulate when young 62. Caulacanthus. 
Frond cellular, solid. Spore-mass suspended ' 63. Hypnea. 
Frond cellular, solid. Spore-mass lateral 64. Pterocladia. 
*** Conceptacles immersed, scattered over the frond. Spore-mass 
parietal 65. Apophlcea. 
II. Tufts of spore-threads not lodged in a hollow conceptacle. 
* Tufts of spore-threads in wart-like excrescences or tubercles. 
Tribe VI. Sqnamarieas. Frond cartilaginous or membranous, horizontally expanded 
and rooting from the under surface. Spores in moniliform strings within the wart. 
Frond red-brown, flat, fan-shaped 66. Peyssonnelia. 
** Tufts of spore-threads immersed in the frond. 
Tribe VII. Sielmmthocladiese. Frond cylindric, gelatinous or submembranons , 
almost wholly composed of filaments set in loose gelatine. Tufts of spores spherical, of 
branching moniliform spore-threads springing from a central point. 
Outer stratum of moniliform filaments lying in gelatine .... 67- Nemalion. 
Outer stratum membranous, thin, of angular cells 63. Scinaia. 
*** Tufts of spore-threads naked, surrounded with an involucre of branchlets of the frond. 
Tribe VIII, Wrangell ese. Frond filiform, of one articulate tube, which is naked or 
coated with small cells. Spores pyriform, in the terminal cells of branching spore-threads. 
Frond filiform, clothed at the nodes with flaccid capillary filaments 69. Wrangelia. 
Series B. Spores iti simple or compound globose masses, enclosed in a 
hyaline mucous or membranous coat. Spore-masses naked or immersed in 
the frond, or contained in conceptacles. 
I. Frond inarticulate, flat or cylindric. 
Tribe IX. Hhodymemese. Spore-masses in globose conceptacles ( sunk in the frond 
in Dasyphloea). Spores first developed in the cells of m.onilform branching filaments 
issuing (from a centre, at length aggregated without order. 
* Frond broad, leafy, dichotomous. 
Conceptacles hemispheric, scattered. Tetraspores crucially divided 70. Rhodymenia. 
Conceptacles spherical, submargiual. Tetraspores transversely 
divided 71- Rhodophyllis. 
Conceptacles sunk in the frond 72. Dasyphlcea. 
** Frond slender, pectinate-pinnaiifid . 73. Plocamium. 
Tribe X. Cryptonemieae. Spore-masses in conceptacles or sunk in the frond. Spores 
developed within solitary or clustered detached cells, at length aggregated, without 
order. 
