CoLLins AND Howe: SPECIES OF HALYMENIA 175 
more homogeneous refringent protoplasts; cortex and. subcortex 
of frond rather distinctly filamentous; subcortex consisting of a 
close network of anastomosing filaments, the stellately branched 
nodal cells mostly 13~20 » in diameter; cortex I-4 cells thick, the 
superficial cells (protoplasts) 3-10 » in diameter in surface view, 
mostly obtuse and more or less isodiametric, sometimes broader 
than high, or, 1.5-2 times higher than broad and subacute, often 
segregated in groups of 2-8, their outer walls very gelatinous and 
deliquescent; tetrasporangia (protoplasts) 18-26 X 13m, the 
spores decussately paired; cystocarps numerous, minute, com- 
monly slightly protuberant on one face, the spore-mass turbinate, 
120-240 yp in diameter. 
Fiorma: Unattached, Jupiter Inlet, Mrs. G. A. Hall, Sep- 
tember 14, 1896 (Phyc. Bor.-Am. 7490 and 749¢, as H. floridana); 
M. A. Howe 1252-1255, October 13, 1902; Indian River Inlet, 
Mrs. G. A. Hall, May, 1899 (Phyc. Bor.-Am. 7494, as H. floridana, 
and 750, as H. floridana, forma dentata); Key West, Mrs. G. A. 
Hall. 
Norta CaroLtna: Bogue Beach, Beaufort, W. D. Hoyt, 
August 12 and 16, 1907. 
Type: Jupiter Inlet, Florida, October 13, 1902, M. A. Howe 
1252, sheet C, in herb. N. Y. Botanical Garden. 
The plant is known locally in the Jupiter Inlet region as the 
“beefsteak”’ seaweed. In form and color of the thallus, as well 
as in size and form of the cystocarps, Halymenia Gelinaria bears a 
remarkable resemblance to H. floridana; in fact, for two species 
that differ so much in the structure of the cortex, the similarity 
is astonishing. The affinities of H. Gelinaria are, however, clearly 
with H. Floresia, a species that it resembles much less in general 
habit. From H. Floresia, it differs chiefly in forming broad, 
entire or subentire membranes, which may reach a length or width 
of 60 cm., and in the less often acute, more isodiametric, super- 
ficial cells. H. Floresia, in typical forms, was found floating with 
it in Jupiter Inlet (Howe 1231) without intergrading conditions. 
When lobules, proliferations, or teeth occur in H. Gelinaria, they 
are very irregularly disposed, while in H. Floresia the branching 
is manifestly pinnate, or rather, bi-tri-pinnate. The main axes 
in H. Floresia may vary a good deal in width, but we have nee 
seen them any broader than 7 cm. and they are rarely more than 
