26 RHODOMELACE^. 



V. 



tion of that variable plant. Turner describes the frond much more compressed 

 than I find it in the specimen preserved in Mr. Menzies' Herbarium. A cross sec- 

 tion after expansion shows the branches to be nearly cylindrical. 



4. Rhodomela subfusca, Ag. ; frond filiform, much branched ; the branches irregu- 

 larly divided, clothed with pinnated branchlets, and subulate, simple, scattered or 

 subfasciculate ramuli ; pinnules subulate, terete ; conceptacles subsessile ; tetra- 

 spores in the somewhat swollen, (but neither moniliform nor attenuated) terminal 

 ramuli (in summer), or in proper branching stichidia issuing irregularly from old 

 stems (in winter.) Ag. Sp.Alg.vol. \. p. 378. Harv. Phyc. Brit. ^.264. Lophura 

 cj/mosa, Kiltz. Sp. Alg. p. 850. 



Has. On rocks and stones near low water mark. Halifax, W. H. H. ; Boston, 

 Dr. Durhee! Lynn, Mrs. Estes! Boar's Head, New Hampshire, Capt. N. Pike ! New- 

 port, Rhode Island, Prof. J. W. Bailey! Staten Island, New York. (v. v.) 



Fronds tufted, 6-12 inches long, quarter to half a line in diameter at base, 

 filiform, attenuated upwards, much branched and bushy. Branches alternate, 

 distichous or subspirally inserted, the secondary ones decompound, about bipinnate ; 

 tertiary branches furnished in the lower half with simple, alternate, sub-distant, 

 subulate ramuli ; above furnished with more compound, pinnulate or multifid 

 ramuli, which are densely crowded about the ends of the branches. Conceptacles 

 ovate, nearly sessile (not seen on American specimens). Tetraspores contained in 

 the terminal, subulate or slightly fusiform, terminal ramuli, solitary or in pairs, 

 not wider than the places where they occur. Colour, a dark, brownish red, be- 

 coming much darker in drying. Substance cartilaginous, somewhat rigid. In 

 drying, the plant adheres, under pressure, to paper, but not with much force. 



In winter the smaller branches fall away, leaving a few naked stems, and at that 

 season tetraspores are frequently found in little, lateral, accessory stichidia, emitted 

 ■vvithout order by the broken branches. In spring, these denuded plants put forth 

 a profusion of pinnato-multifid branches, being much more bushy than plants of 

 the first season. 



My Halifax specimens are very robust. The rest are of the ordinary form so 

 common in Europe. 



.5. Rhodomela gracilis, Kiitz. ; frond flaccid, ultra-setaceous below, soon divided 

 and then excessively branched and bushy, decompound pinnate ; the branches 

 setaceous below, capillary above, repeatedly divided alternately ; penultimate ramuli 

 distant, dichotorao-multifid above the middle, attenuate ; conceptacles pedicellate, 

 somewhat racemose ; tetraspores in the attenuated, moniliform, terminal ramuli. 

 Lophura gracilis, Kiitz. Sp. Alg. p. 850. Rhodomela suhfusca (in partj Ag. I. c. supra. 

 Lyngh. Eyd. Dan. t. Md.fig. B. C. Tab. XIII. C. 



