Ser. MELANOSPERME^. ( 65 ) Fam. DICTYOTE^. 



Plate CLIII. 

 CHORDA LOMENTARIA.— iy^/y/i. 



Gen. Char. — Frond cartilaginous, simple, filiform, cylindrical, tubular ; the tube divided 

 at regular intervals by transverse septa. Fructification : obconical spores, forming 

 a dense stratum over the whole external surface of the frond, and "mixed with 

 elliptical antheridia (?) " Name from chorda, "a chord." 



Chorda lomentaria (?). — Frond membranaceous ; septa distant, at very 

 irregular intervals, and marked by external constrictions, intervals some- 

 what inflated. 



Chorda lomentaria. — Lyngh. Hyd. Dan. p. 74, t. 18 ; Grev. Ahj. Brit. p. 48 

 Hook. Brit. Fl. vol. ii. p. 276 ; Wyatt, Alg. Damn. No. 6; E. Bot. 

 Suppl. t. 2902 ; /. Ag. AJg. Medit. p. 45 ; Harv. in Mack. Fl. Hih. 

 parts, p. 174; Harv. P. B. plate 285; Harv. Man. p. 32; Harv. 

 Syn. p. 30; Atlas, plate 8, fig. 32; Harv. N. B. A. part 1, p. 98. 



Chorda fistulosa. — Zanard. Syn. Alg. Adr. p. 87. 



ScYTOSiPHON lomentarium. — Endl. 3rd Suppl. p. 25 ; J. G.Agardh, Sp. Gen. Alg. 

 vol. i. p. 126. 



ScYTOSiPHON filum, var. 7. — Ag. Spec. Alg. vol. i. p. 162; Ag. Syst. p. 257. 



SoLENiA fuscata. — Bory, Moree, No. 1485. 



AsPERococcrs castaneus. — Carm. Hook. Br. Fl. vol. ii. p. 277. 



Chlorosiphon Shuttlewoo'thianus. — Kiltz. Phyc. Gen. p. 301. 



Hab. — On rocks, stones, &c., in tide-pools. Annual. Summer and autumn. Very 

 common. 



Geogr. Dist. — Atlantic shores of Europe ; Mediterranean Sea ; North and South 

 America ; Japan ; Southern and Antarctic Oceans. 



Desckiptiox. — Root, a minute disc. Fronds much tufted, from six 

 to ten inches or more in length, and from one to three lines in diameter 

 in the middle, much attenuated at the base, and tapering at the summit 

 to an obtuse point, much constricted at very unequal distances, surface 

 smooth but not lubricous, tubular upwards, solid at the base, very 

 slender and cylindrical, the intervals between the constrictions somewhat 

 inflated, in the young state cylindi'ical throughout, and without con- 

 strictions, the stracture consisting entirely of small cells, gradually 

 becoming more minute towards the circumference, roundish hexagonal. 

 In old plants the surface becomes coated over with a stratum of densely 

 packed moniliform radiating filaments, which may in some way or other 



VOL. in. K, 



