HOWE: PHYCOLOGICAL STUDIES 503 
filamentous or rhizoidal medulla bordered by mostly two irregular 
series of large cells 240-340u in maximum diameter in cross section, 
their walls rather firm, not gelatinizing much in fresh water or 
glycerin, remaining about 6-15 thick, the large cells passing 
somewhat abruptly into the small cells of the outer cortex; the 
zonate sporangial tetrads irregularly ovoid, 55-85 in long diameter; 
other parts not seen. [PLATE 29.] 
- La Paz, Vives 7 (type), rzc, 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. 932, as ‘‘Anatheca furcata 
Setchell & Gardner ms.” and afterwards described and figured 
in Univ. California Publ. Bot. 1: 310. pl. 23. f. 39; pl. 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 aré 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., 250u thick in younger parts, becoming 500-700u 
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—400u 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 
thick: antheridia beginning as shallow pockets in the cortex, soon 
becoming more or less confluent and covering a large part of the 
