46 RHODOMELACE^. v. 



renders it, after it has once been seen, easily recognised in the several varieties it 

 assumes. It is the only species yet found in Charleston Harbour, where in January 

 and February it is very abundant. It extends north as far as Boston, where it is a 

 summer plant. In Europe it is a characteristic Adriatic species, and is found along 

 the Atlantic coast as far as the south of England. 



19. PoLYSiPHONiA parasitica^ Grev. ; filaments slender, rigid, full red, decom- 

 pound-pinnate, distichous ; branches bi-tri-pinnate ; pinnules closely set, alternate, 

 erecto-patent, awl shaped, acute ; internodes about as long as broad, about four- 

 banded ; dissepiments hyaline, wavy ; tubes about eight ; conceptacles ovate, on 

 short stalks ; tetraspores immersed in swollen pinnules. Grev. Fl. Edin. p. 309- 

 Haw. Phyc. Brit. t. 14?. Ag. Sp. Alg. 2, p. 103. Kutz. Sp. Alg. p. 803. 



Hab. Providence, Rhode Island (fide Sp. in Herb., Hooper). 



One to three inches high, distichous, repeatedly pinnate. Colour when growing 

 a clear lake-red, becoming brownish in drying. It imperfectly adheres to paper. 



Apparently a rare species in America. I have only seen a solitary specimen in 

 the collection of Mr. Hooper of Brooklyn. It is a beautiful plant resembling a 

 miniature Ptilota in outward aspect. 



20. PoLTSiPHONiA Pecten Veneris ; small (1-2 inches high), capillary, alternately 

 branched ; branches flexuous, sometimes many times compound, spreading or 

 reflexed ; lesser branches pectinated on one side with secund, bristle-shaped, short 

 ramuli, issuing from every node ; internodes nine or ten tubed, about once and 

 half as long as broad, those of the ramuli shorter ; tetraspores immersed in the 

 ramuli ; conceptacles ovato-rostrate, on long peduncles ! Var. a. much branched, 

 the comblike branches strongly recurved. (Tab. XVI. C.) Var. /3. less branching, 

 the comblike branchlets elongate, straight or nearly so. (Tab. XVI. D.) 



Hab. On small Algaj and corallines. Key West, W. H. H. (20). Dr. Blodgett, (70). 

 Pine Islands, Prof. Tuomey (26). (v. v.) 



Filaments decumbent at base and creeping, then erect, capillary or subsetaceous, 

 much branched, distichous. Branches alternate, flexuous, spreading at wide angles, 

 repeatedly divided, the successive divisions usually secund. All the lesser branches 

 and portions of the branches and stem are furnished, at intervals of less than a quar- 

 ter of a line, with secund, subulate, or bristle-shaped ramuli about a line in length, 

 so that each penultimate branchlet with its ramuli resembles a miniature comb. 

 These little combs in the larger and more branching specimens are generally 

 strongly reflexed, the ramuli curving in an o])posite direction. A transverse sec- 

 tion of the stem shows nine or ten tubes. The internodes are rather longer than 



