See. MELANOSPERME/E. (13) Fam. FUCACE^. 



Plate CXXXV. 

 PYCNOPHYCUS TUBERCULATUS.— ^'wfe. 



Gen. Char. — Frond subcartilagiuoiis, dichotomous, cylindrical ; ixiot fibrous ; air-vessels 

 innate ; receptacles terminal, containing immersed spherical conceptacles, com- 

 municating with the surface by a terminal pore, and containing attached to their 

 inner surface obovate spores mixed with antheridia. Name from TrvKvhs, "thick," 

 and (pvKos, "saa-weed." 



Pycnophtcus tuherculatiis. — Frond simple or reg'ularly dichotomous, 

 with wide axils ; receptacles terminal, linear, often subtended by a 

 vesicle. 



Ptcnophtoits tuberculatus. — Kutz. Phjc. Gen. p. 359 (1843) ; Barv. P. S. plate 89 ; 

 Earv. Man. p. 18 ; Harv. Syn. p. 16 ; Atlas, plate 3, fig. 9. 



Cymaduse tuherculata. — Dne. Ann. Sc. Nat. 1845, p. 12. 



Fucus tuberculatus. — Etuds. Fl. Angl. p. 588 ; Good. <fc Woodw. in Linn. Trans. 

 vol. iii. p. 198 ; Turn. Syn. Fuc. vol. ii. p. 505 ; Turn. Hist. t. 7 ; 

 Esper, Ic. Fuc. vol. ii. p. 20, t. 121 ; E. Bot. t. 726 ; Lamour. Ess. 

 p. 20; Stack. Ner. Brit. Append. ; Ag, Sp. Alg. vol. i. p. 98; Ag. 

 Syst. p. 279 ; Spreng. Syst. Veg. vol. iv. p. 316 ; Grev. Alg. Brit. 

 p. 18 ; Hooh. Br. Fl. vol. ii. p. 269 ; Harv. in Mach. Fl. Hib. part 3, 

 p. 169; Harv. Man. 1st ed. p. 21; Wyatt, Alg. Danm. No. 103; 

 Endl. 3rd. Suppl. p. 29 ; /. G. Agardh, Sp. Gen. Alg. vol. i. p. 204. 



Fucus bifurcatus.— With. vol. iv. p. 109, t. 17, fig. 1. 



Hab. — In rock -pools left on the recess of the tide near low- water mark, never growing 

 in places which are dry at low water. Perennial. Summer and autumn. Coasts of Corn- 

 wall and Devonshire ; Ilfracombe ; Portland ; north of Ireland. Common on the west 

 coast of Ireland from Gal way to Cork ; Jersey. 



Geogr. Dist. — Atlantic shores of France and Spain ; coast of Barbary ( Web. and 

 Mohr) ; Cape of Good Hope (Bowie and Dr. Harvey). 



Description. — Root composed of stout, creeping and interlacing 

 fibres. Fronds much tufted, eight to twelve inches or more in length, 

 two to three lines in diameter, cylindrical, with a naked stem for three 

 to six inches, then regularly dichotomous or alternately subpinnate, 

 with wide rounded axils ; branches cylindrical, short, not tapering, 

 terminated by the long, linear, tubercular receptacles, which generally 

 terminate every branchlet, and are obtuse or very slightly tapering 

 at each end, their structure similar to that of the stem, of which they 

 are mere prolongations ; the axis of rather large roundish oblong cells, 



