50 RHODOMELACE^. v. 



branches ; branches bi pinnate, both pinnfe and pinnules distant, very slender 

 and irregularly placed ; internodes of the branches 4-8 times, of the pinnules 

 twice or thrice as long as broad ; tubes twelve. 



e. tenuis ; stem setaceous, decompound-pinnate ; branches sub-distichous, ovate 

 in outline, 3-4 times pinnate ; the pinnae; and pinnulae patent and rather 

 distant, not fastigiate ; internodes of the pinnte 3-4, of the pinnules 2-3 

 times as long as broad ; tubes fifteen. 



Var. C Meiiziesil ; setaceous, alternately branched, distichous ; branches virgate, 

 bi-pinnate ; pinnae sub-distant, pinnula3 subulate, the lowermost squarrose or 

 revolute, simple, the upper erecto-patent, simple or alternately multifid ; inter- 

 nodes of the branches twice or thrice as long as broad, of the ramuli shorter 

 than their breadth ; tubes twelve or thirteen. 



f). disticha ; stem setaceous, decompound-pinnate, distichous ; branches bi-tri- 

 pinnate, with a subdefined, oblong or ovate outline, the pinnte and pinnulas 

 remarkably patent ; internodes of the pinnae rather shorter than their breadth, 

 of tlie pinnules as long as broad ; tubes eleven or twelve. 



0. Durkeei ; robust, compressed, decompound-pinnate, distichous ; branches with 

 a definite, oblong outline, bi-tripinnate ; pinnce naked at base, pinnulate above, 

 pinnules erect ; all the internodes much shorter than their breadth. Pol. 

 Durkeei Harv. MSS. (Tab. XVII. C.) 



Hab. In rock pools between tide marks, and in deep water, attached to rocks 

 and shells, &c. Perennial. Var. a Sitcha, Barclay ! Prince Edward's Island, 

 Dr. Jeans. Nahant, W. H. H. IVewbviryport, Miss Townsend. Staten Island, 

 Prof. Bailey. Red Hook and Fort Hamilton, Messrs. Hooper., Pike., Walters., (^'C, 

 W. H. H. /?. Halifax, W. H. H. y. New Bedford, Dr. Roche. S. Yellow Hook, 

 New York, Mr. Walters, e. Ship Anne Point, Messrs. Walters and Hooper. Bos- 

 ton Bay, Capt. Pike. New Bedford, Dr. Roche. ?. West Coast, .4. Menzies, Esq. 

 (1788). 7). Newport, J/r. Olney. Long Island Sound, Cap>t. Pike. Fort Hamil- 

 ton, Messrs. Hooper., Walters, Congdon. 0. Germautown, Dr. Durkce. New Haven, 

 Dr. Durkee and Mrs. Bahcock. 



Some of the above varieties are so unlike the normal form of this species (our 

 var. a.fucoides), that were there not intermediate states they might readily pass for 

 distinct species. The number of tubes in the stem is extremely variable in differ- 

 ent specimens, even where there is no other difference. In some I have found them 

 as few as eleven, in others as many as eigliteen ; the more common numbers being 

 twelve and fifteen. The length of the internodes is more constant in the several 

 varieties, when the penultimate divisions of the frond are compared. The best 

 general marks for the species are its decompound, pinnate branching, penultimate 

 ramuli, naked below and pinnulate above the middle, and many tubed internodes of 

 moderate leng-th. 



Var. a. fucoides. Stems 6 12 inches long, as thick or twice as thick as hog's 

 bristle, rigid below, flaccid above, many times decompound ; the lesser branches 

 very dense and bushy, of equal length ; the ultimate ramuli very erect, fastigiate. 



