MARINE ALG^ OF BEAUFORT, N. C. 537 



uu. Texture rather cartilaginous; frond coarse, i to 1.5 mm. in diameter, 

 sparingly branched, small branches few, usually coarse 



Gracilaria multipartite (p. 484). 



uuu. Texture cartilaginous, wiry ; frond coarse, densely branched, branches 

 interwoven, beset with many short, coarse, blunt branchlets 



LAURENCIA (p. 497). 



bbbb. Frond flattened v . 



v. Frond i to 25 mm. wide in widest part w. 



w. Frond regularly dichotomous x. 



x. Frond 4 to 12 mm. wide in widest part, 2 to 8 cm. long, membranaceous, fleshy, 



rather thick, edges smooth ; red or pink ' RHODYMENIA (p. 487). 



xx. Frond 12 to 25 mm. wide in widest part, 3 to 10 cm. long, fleshy, rather coarse, 



edges ruffled; purple CRYPTONEMIA (p. 521). 



xxx. Frond 10 to 25 mm. wide in widest part, 6 to 20 cm. long, thin membranaceous, 



veined, edges wavy, slightly proliferous; bright pink NITOPHYLLUM (p. 494). 



ivw. Frond pinnately or irregularly branched y. 



y. Frond not more than i mm. wide, fleshy, rather densely pinnately or irregu- 

 larly branched; dark purple Grateloupia filicina (p. 521). 



yy. Frond 6 to 18 mm. wide in widest part, fleshy, main axis conspicuously larger 

 than branches, densely decompound distichously branched, branches 

 sometimes dichotomous, all branches flat, numerous branchlets frequently 



arising from the flat surfaces; purplish green. Grateloupia gibbesii (p. 521). 



yyy. Frond 9 to 15 mm. wide in widest part, gelatinous, main axis conspicuously 

 larger than branches, sparingly distichously branched, ultimate branches 



rounded; pink Halymenia floresia (p. 518). 



w. Frond 40 to 130 mm. wide in widest part z. 



2. Frond very thin membranaceous, delicate of. 



a'. Frond pink, simple or sparingly branched, bearing a conspicuous midrib and 

 sometimes fine pinnate veins; fruit appearing as conspicuous dots on 



surface GRINNELLIA (p. 495). 



oaf. Frond purple, simple or irregularly divided into lobes, structure uniform; 



fruit not visible to naked eye PORPHYRA (p. 464). 



zz. Frond firm, membranaceous or fleshy b'. 



b'. Frond dichotomously branched AGARDHINULA (p. 488). 



bb'. Frond simple or lobate, not dichotomous </. 



cf . Frond fleshy-cartilaginous, coarse, simple, or irregularly divided into lobes 

 not reaching to the base, sometimes proliferous from the margins, stem 

 inconspicuous; cystocarpic fruit borne in conspicuous, short protuberances 

 arising from edges and surface; usually dark red, sometimes yellowish 



MERISTOTHECA (p. 479). 



cd ' . Frond firm membranaceous, thin, usually divided into several more or less 

 regular ovate or elliptical lobes arising from the base on distinct stalks; 

 fruit in inconspicuous dots on surface; purplish pink. .. .Halymenia floridana (p. 519). 



ccd ' . Frond gelatinous-fleshy, light pink, sometimes with yellowish tinge df. 



d'. Frond simple or divided into several lobes borne on distinct stalks; frond 



or lobes ovate Halymenia gelinaria (p. 518). 



dd' '. Frond simple or irregularly divided into lobes; frond or lobes lanceolate 



Chrysymenia agardhii (p. 490). 



aa. Frond incrusted with lime e'. 



ef . Frond erect, filiform, jointed ./'. 



/'. Conceptacles immersed, scattered over the segments AMPHIROA (p. 526). 



ff' '. Conceptacles immersed in the apices of terminal segments, opening by terminal 



pores, the fertile segments sometimes bearing hornlike lateral branches. CORALUN A (p. 527). 



