174 Collins and Howe: Species of Halymenia 



simplice vel parce subconformiter divisa, margine plana, Integra 

 vel irregulariter dentata aut crenulata, nonnunquam fimbriata; 

 medulla frondis laxa vel subvacua, filamcntis transversalibus 

 crebris, fills stellatis paucis et inconspicuis; strato subcorticali 

 dense filamentoso, filamentis anastomosantibus, celluHs nodalibus 

 majoribus; strato cortical! series 1-4 cellularum monstrante, 

 parietibus cellularum mollissimis, gelatinoso-deliquesccntibus; 

 tetrasporangiis dccussatim divisis; cystocarpiis numerosis, minutis, 

 ad una pagina frondis plerumque prominulis, massa sporarum 

 turbinata, 120-140 fi diam. 



Species colore, habitu, cystocarpiorum forma, H. floridanae 

 J. Ag. proxima, sed dilTert thallo multo magis gelatinoso, plerum- 

 que crassiore, cortice manifeste filamentoso, nee pseudoparen- 

 chymato, fills stellatis minus evolutis. Structura H. Floresiae 

 (Clem.) Ag. similis, habitu differt, fronde latiore Integra vel sub- 

 integra, nee regulariter pinnata. 



Ad oras Floridae et CaroHnae Septentrionalis (typum legit 

 M. A. Howe in loco "Jupiter Inlet" dicto ad oras Floridae, Oct, 

 13, 1902, no. 1252). 



Thallus short-stipitate from a small basal disk; stipe 3-5 mm. 

 long, 0.75-1 .2 mm. thick, cuneate from a subterete base ; frond plane, 

 membranous or carnose-membranous, usually very gelatinous, 

 60-600* ^t thick, suborbicular, oblong, ovate, or cuneate-obovate, 

 attaining a width of 5 cm. to 6 dm., subentire or rather sparingly 

 (usually conformably) parted, lobed, or proliferous, the margins 

 entire or very irregularly lobulate, dentate, erose-crenulate, or 

 occasionally laciniate-fimbriate; surface dull, smooth; color 

 pinkish vinaceous, rocellin-purple, vinaceous purple, or deep 

 hellebore-red ;t medulla of stipe 0.45-0.75 mm. thick, moderately 

 compact, gelatinous; cortex of stipe gelatinous, mostly 8-1 5 cells 

 thick; medulla of frond moderately compact or subvacuous, its 

 filaments mostly 8-14 ix in diameter, many of them obliquely 

 transverse, connecting the opposite subcortical layers, the cells 

 mostly 20-70 iJL long, the medulla occasionally showing a few 

 rather inconspicuous stellate ganglia with nodes 20-40 /x in 

 diameter and slender, elongate, rigid, straight or flexuous, now and 

 then tortuous or nodulose, usually long-celled, radiating filaments, 

 these commonly 4-7 n in diameter, the ganglionic system with 



* The minimum is drawn from the thinner parts of dried specimens, as shown 

 when sections are soaked out with water; the maximum is from the older parts as 

 shown in formalin-preserv'ed material. 



t Ridg\vay, loc. cit. i>l. 27 and 38. 



