Ser. Melanosperme^:. Fara. DieU/oteet. 



Plate CVII. 

 CHORDA FILUM, Lanumr. 



Gen. Char. Root scutate. Frond simple, cylindrical, tubular ; its cavity 

 divided by transverse, membranous septa, into separate chambers. 

 Fructification ; a stratum of obconical spores, much attenuated at the 

 base, covering the whole external surface of the frond. Among these 

 are found elliptical anther idia (?). Chorda {Stack.) — a cord. 



Chorda filum-, frond cartilaginous, lubricous, clothed with pellucid hairs, 

 filiform, very long, tapering to each extremity, not constricted at the 

 dissepiments. 



Chorda filum, Lamour. Ess. p. 26. Byngb. Hyd. Ban. p. 72. t. 18. Hook, 

 in Fl. Lond. N.S. t. 204. Grev. Alg. Brit. p. 47. t. 7. Hook. Br. Fl. 

 vol. ii. p. 276. Harv. in Mack. Fl. Hib. part 3. p. 174. Harv. Man. 

 p. 36. Wyatt, Alg. Banm. no. 159. Kiitz. Phyc. Gen. p. 334. t. 29. 



Chordaria filum, Ag. Syn. p. 13. Hook. Fl. Scot, part 2. p. 98. 



Scytosipho* filum, Ag. Sp. Alg. vol. i. p. 161. Ag. Syst. p. 257. Grev.Fl. 

 Edin. p. 288. Spreng. Syst. Veg. vol. iv. p. 328. Endl. 3rd Suppl. p. 25. 



Fucus filum, Linn. Sp. Fl. p. 1631. Stack. Ner. Brit, t, 10. Turn. Hist. 



t. 86. Eng. Bot. t. 2487. 

 Fucus tendo, Esper, Ic. t. 22. 

 Ceramium filum, Roth, Cat. Bot. vol. i. p. 147. 



Var. /3. tomentosa; of small size, more densely clothed with coloured, olive 

 or green hairs. 

 Chorda tomentosa, Lyngb. Hyd. Ban. p. 74. t. 19. 



Hab. On rocks and stones in the sea, commencing within tide marks, and 

 extending in still water to the depth of ten or fifteen fathoms. An- 

 nual. Summer and Autumn. Very abundant on the shores of the 

 British Islands. 



Geogr. Distr. Abundant throughout the North Atlantic, on the shores of 

 Europe and America. Coast of Brazil. Also in the North Pacific, at 

 Sitka, Unalaschka and Kamtschatka. 



Descr. Root, a minute disc. Fronds tufted, one to twenty, or in still water 

 even forty feet in length, scarcely twice as thick as a bristle at the base, 

 gradually increasing in thickness to the middle, and there from a quarter 

 to half an inch in diameter, and again gradually diminishing toward the 

 apex, which is of equal tenuity with the base, cylindrical, hollow, divided 

 at short intervals, by very thin membranes, into chambers or joints, which 

 are not visible externally, very lubricous or slimy, clothed at an early stage 

 with very dense, slender, gelatinous filaments, which generally disappear as 

 the plant advances to maturity, but may sometimes be found on old plants. 

 Substance cartilaginous and firm, very tough when recent. Fructification 

 covering the whole surface of old plants, consisting of obconical, vertical 

 spores, supported on long pedicels, l>\ winch thc\ arc fixed to the outer 



1) 



