Howe: Phycological studies 503 



filamentous or rhizoidal medulla bordered by mostly two irregular 

 series of large cells 240-340^ in maximum diameter in cross section, 

 their walls rather firm, not gelatinizing much in fresh water or 

 glycerin, remaining about 6-15/i thick, the large cells passing 

 somewhat abruptly into the small cells of the outer cortex; the 

 zonatesporangial tetrads irregularly ovoid, 55-85/1 in long diameter; 

 other parts not seen. [Plate 29.] 



La Paz, Vives 7 (type), 11c, 18b, and 20a. 



Although our specimens are either sterile or tetrasporic, we 

 have little hesitation in considering this plant a close relative of 

 the one from Whidbey Island, Washington, distributed in the 

 Phycotheca Boreali-Americana, no. gj2, as "Anatheca furcata 

 Setchell & Gardner ms." and afterwards described and figured 

 in Univ. California Publ. Bot. 1: 310. pi. 23. f. jq; pi. 24. f. 41. 

 1903. However, we are at present unwilling to regard them as 

 forms of one species. Anatheca furcata reaches a width of 2-3 cm., 

 while A. dichotoma is mostly only 1-7 mm. wide; it is once to 

 thrice forked, while A. dichotoma is commonly 8-10 times forked; 

 A. furcata also has a darker red color, a longer, more attenuate 

 stipe, and its cell walls are more inclined to gelatinize on being 

 soaked out with fresh water, which fact is doubtless responsible 

 for giving specimens a less rigid and cartilaginous habit than 

 those of Anatheca dichotoma. 



Gracilaria Vivesii sp. nov. 



Thallus membranaceous, complanate, regularly and flabellately 

 dichotomous (4 or 5 times forked in specimens seen), attaining a 

 length of 14 cm., 250/i thick in younger parts, becoming 500-700^ 

 below, broadly cuneate or inversely deltoid at base; the lower 

 segments subquadrate or cuneate-oblong, 8-20 mm. broad below, 

 becoming 10-35 mm - broad under the dichotomies; segments of 

 the two ultimate dichotomies considerably narrower, oblong or 

 somewhat linear-oblong, 7-10 mm. wide, diminishing to 4-6 mm. 

 in the terminal; margins entire, axils rounded, dichotomies patent 

 or occasionally somewhat divaricate, apices rounded-obtuse, color a 

 vinous- or coralline-red fading to light greenish pink; medulla com- 

 posed of two or three irregular series of subglobose, ovoid or some- 

 what flattened nearly empty cells 50-400/x in diameter, bounded by 

 one or two series of much smaller subglobose or flattened sub- 

 cortical cells; cortex 1-3-stratose, the surface jelly firm and 13-28,11 

 thick: antheridia beginning as shallow pockets in the cortex, soon 

 becoming more or less confluent and covering a large part of the 



