PL cell. aph. 2.THALASSIOPHYT^E, 29. Callith. 
1. Callith. purpurascens. Purplish, pretty-weed. 
Threads thrice pinnately divided, very slender, membra- 
naceous, purplish red ; branches and twigs spreading; knots 
contracted; joints 3 times as long as broad. 
Conferva marina nodosa, coralloidis montani instar ramosa, Dillm 
Muse. 36. 
Conferva purpurascens, Huds. FI. Angl. 600 ; Engl. Hot. 2465. 
Conferva rosea, Dillwyn Conf. 17. 
Ceramium rose um, Roth Cat. 2, 182. 
Callithamnion roseum, Lyngbye Hydr, Dan. 126. 
Sea-shore, on stones or marine plants. 
Thallus tufted, 2 or 3 inches long ; branches many, alter- 
nate; twigs very numerous; capsules on the upper side of 
the twigs. 
0. rosea. Tuft closer, rose red. 
Conferva rosea, Engl. Bot. 966. 
2. Callithamnion corymbosum. Corymbus pretty-weed. 
Thallus branched like network, corymbose, slender* 
tufted, rose-colour; branches alternate, many-cut, in bun- 
dles; apex 2-cut; joints slightly dilated above, about twice 
as long as broad ; knots pellucid ; thecae ovate, scattered* 
peduncled; peduncles very short. 
Conferva corymbosa, Engl. Bot. 2352. 
Ceramium pedicellatum, Ft. Dan. 1596. 
Callithamnion corymbosum, Lyngbye Hydr. Dan, 125. 
Sea-shores. 
Thallus outline round. 
3. Callithamnion Borreri . Borrer’s pretty-weed l 
Thallus repeatedly branched, hairlike, bright red; 
branches all alternate, spreading in 2 directions, zigzag* 
level-topped; joints cylindrical, about twice as long as 
broad. 
Conferva Borreri, Engl. Bot. 1741. 
Sea-shore; October. 
Thallus tufted, about 2 inches high, becomes orange- 
yellow by weathering, very slender ; twigs corymbose; knots 
slightly contracted. 
4. Callith. thujoides. Arbor-vitce pretty-weed . 
Thallus repeatedly branched, very slender, tufted ; 
branches alternate, zizgag ; side-shoots alternate, com- 
pound; joints very short, cylindrical. 
Conferva thujoides, Engl. Bot. 2205. 
Y 2 
