326 29. Callitli, 2.THALASSIOPHYTiE. Pl.ceU.apL 
13. Callithamnion Rolhii. Roth’s pretty-weed . 
Thallus forked, branched, tufted, upright, short; tuft 
close, scarlet; branches and twigs alternate; joints about 
3 times as long as broad. 
Conferva phoenicia, R. Brown MSS. With Bot. 4, 165. 
Conferva Rolhii, Turton's Syst. Nat. 6,1806; Dillw. Conf. 13 ; Engl . 
Mot. 1702. 
Conferva violacea, Roth Cat. 1, 190. 
Callithamnion Rolhii, Lyngbye Hydr. Dan. 129. 
Sea-shore. 
Tufts oblong, bright red, when dry crimson or purplish; 
thallus about half an inch high ; branches below distant, 
above crowded. 
14. Callithamnion lanuginosum. Woolly pretty-weed. 
Thallus short, slender, mostly branched, light reddish ; 
branches simple, upright, scattered, going out horizontally. 
Conferva lanuginosa, Dillw. Conf. 
Callithamnion lanuginosum, Lyngbye Hydr. Dan. 131. 
On marine plants. 
Threads very minute, coming out horizontally from the 
base, simple or branched above. 
15. C alii ih. flor idulum. Smallflowered pretty-weed. 
Thallus short, slender, tufted, entangled, mostly branch- 
ed, very light rose-red ; branches scattered, mostly simple, 
remote, placed towards the apex ; joints about 3 times as 
long as broad. 
Conferva floridula, Dillw. Syn. 73. 
Rocks on the sea-shore. 
Threads very fine, about half an inch long; becomes dull 
reddish green when dry. 
16. Call'll h. interruptum. Interrupted pretty-weed. 
Thallus branched, short, purplish; branches and twigs 
alternate ; joints dilated above, truncated, about four times 
as long as broad ; thecae lateral, elliptical, with a transverse 
separation, on short pedicells. 
Conferva interrupta, Engl. Bot. 1838. 
On marine plants. 
Thallus dull rose-red, about an inch high. 
17. Callith. pedicellalum. Pedicelled pretty-weed. 
Thallus much branched, forked, hairlike, red ; twigs 
many-cut; joints slightly dilated above, 5 or 6 times as 
