170 Collins and Howe: Species of Halymenia 



Ad oras Insularum Bermudensium (typum legit F. S. Collins, 



Apr. 25, 1912, no. 7074). 



Thallus usually stipitate; stipe commonly 2-10 mm. long, 

 0.45-0.75 mm. thick, subterete below, complanate or costate- 

 alate above, sometimes branched, occasionally more elongate and 

 subrhizomatous; frond membranous, rather firm or slightly 

 gelatinous, 60-120 /j, thick, variable in form, suborbicular, cordate, 

 or obovate, attaining a width of 4-30 cm., subentire, or sparingly 

 or copiously lobed or proliferous, the lobes or proliferations con- 

 formable or ovate, themselves sometimes once or twice lobed in 

 similar fashion, the proliferations often stipitate, the apices 

 rounded-obtuse, the margins plane or more or less ruffled-plicate, 

 subentire, lightly sinuate-crenate, or now and then irregularly 

 coarsely or obscurely dentate; surface dull or rarely subnitent, 

 smooth; color (dried) violet-red (rosolane-purple to Indian lake*); 

 medulla of stipe compact, sometimes pseudoparenchymatous, 

 0.15-0.45 mm. thick; cortex of stipe or of its costa very firm, 

 compact, parenchymatous, 8-30 cells thick, its cells in distinct 

 anticlinal rows, cells of subcortex larger and irregularly disposed ; 

 medulla of frond moderately compact. Its filaments mostly 3-8 n 

 in diameter, usually interspersed (in older parts at least) with 

 coarser filaments, 6-20 /x in diameter, having more homogeneous 

 refringent contents, such filaments radiating from substellate 

 ganglion-like enlargements 15-65 /j. in diameter; cortex of frond 

 parenchymatous or subparenchymatous, 1-3 cells thick, the 

 cells usually firm-walled, subquadrate in section, the superficial 

 cells angular, mostly 5-10 m in diameter in surface view, their 

 outer walls 2-4 /jl thick, protoplasts close (separated 2-3 11), sub- 

 cortex 1-3 cells thick, its cells mostly 13-25 m in diameter; tetra- 

 sporangia 12-16 fx X 8-10 fx; cystocarps unknown. 



Bermuda: In shallow water in clefts of rocks and caves and 

 among roots of Rhizophora; A. F. Kemp, August, 1856 (as 

 Rhodymenia palmata); Walsingham, W. G. Farlow, February, 

 1881 ; near Hamilton, M. A. Howe 69, June 12, 1900; Stokes Bay, 

 Tucker's Town, M. A. Howe 313, July 6, 1900; Harrington Sound, 

 A.B. Hervey, January 15, 191 3; Dingle Bay, A. B. Hervey, March 

 30, 191 5; Grasmere, A. B. Hervey, March 9, 191 4; Old Ferry, 

 A. B. Hervey, April 2, 191 3; Castle Harbor, F. S. Collins, April 

 25, 1912 (Phyc. Bor.-Am. 20^0), and May 3, 1913. 



Type: Castle Harbor, near Tucker's Town, April 25, 1912, 

 F. S. Collins 7074, in herb. F. S. Collins. 



* Ridgway, R. Color standards and color nomenclature /jJ. 26. 1912. 



