$24 29. Callith. 2. THALASSIOPHYT/. Pl. cell. aph. 
Sea-coast; September, October. . 
~ Thallus tufted, 1 or 2 inches long; joits of the stem + 
to 6 times as long as broad, of the twigs only as long. 
5. Callith. tetragonum. Four-sided pretty-weed. 
Thallus much-branched, red; ‘wigs bundled, short, 
spreading horizontally attenuated at bottom, pointed at 
the tip ; jozs ovate-cylindrical, twice as long as broad. 
Conferva tetragona, Withering Bot. 4,405; Engl. Bot. 1690. 
Sea-shore, or parasitical on other sea-plants. 
Thallus tufted, 2 or 3 inches long; branches 4-sided, 
sides hollowed ; joinis of the twigs about as long as broad; 
thece. globular. . 
6. Callithamnion telricum. Dirty pretty-weed. 
Thallus several times pinnated, brown red, lurid; seg- 
ments and lobes alternate; points rather curved; joints 
about 3 times as long as broad; thece single, slightly pe- 
dicelled. 
Conferva tetrica, Dillwyn Conf. 81; Engl. Bot. 1915. 
Sea-shore, on stones and marine plants. 
Stems many, tufted, 6 or 8 inches high, alternately 
doubly pinnate; ‘wigs pinnate; joints equal. 
7. Callithamnion Hookeri. Hooker's pretiy-weed. 
Thallus very much branched; stem thick, not visibly 
jointed, pale reddish-brown; twigs crowded, short, pin- 
nate; lobes alternate, jointed; joimts rather longer than 
broad. 
Conferva Hookeri, Dillw. Conf. 106. 
- Sea-shore. 
8. Callithamnion jfloccosum. Flock pretty-weed. 
Thallus branched, rose-colour; branches alternately pin- 
-nated ; segments opposite, pectinated, horizontally recurved ; 
lobes pointing one way 3 joints about 3 times as long as 
broad. 
Conferva Turneri, Engl. Bot. 1637. 
Conferva Plumula, Ellis Ph. Tr. 57,425; Diliw. Conf. 50. 
Conferva floccosa, Fi. Dan. 828. 
Ceramium floccosum, Roth Cat. 2,185. 
- Ceramium Plumula, 4gardh Syn, 62. 
Sea-shore; May to July. 
Thece sessile, globular, on the lobes. 
