ALG OF MID-LITTORAL MARSH 63 
not attached by holdfasts, but simply les in curly, twisted tangles among the 
stems of the Spartina. It also differs from these markedly in structure. The 
individual plants vary in length from 1 to 3 dm., and have a nearly constant 
width from end to end of about 8 mm. The midrib is not at all prominent, 
cryptostomata and vesicles are rare, and fruiting branches have never been seen 
on this variety here during the summer season, nor on the April and October 
visits. From the absence of any receptacles on the older plants and also of any 
sporelings or very young plants, it seems evident that this variety does not 
frequently propagate itself sexually. From the mode of growth of this alga, 
in tangles not attached by holdfasts, and from the occurrence of small broken- 
off bits floating about in the water, it is highly probable that the chief mode of 
propagation is this purely vegetative one, resembling that of the well-known 
Sargassum bacciferum. | 
The question now arises concerning the relation of this form to the typical 
F. vesiculosus. In view of the absence of receptacles on F’. spiralis, the sug- 
gestion occurs that the plants of this variety may ultimately arise only from 
odspores or fragments of typical plants of FP. vesiculosus. Portions of the 
thallus of this species of the variety growing on the wharves were tangled in 
wire netting and left for four weeks among the Spartina on the Spit. At the 
end of this time the tips of most of the plants had begun to assume the charac- 
teristic spiral twist of the variety spiralis. In the following spring some of the 
spiral plants developed from the fragments showed 4 inches of spirally twisted 
thallus. It may be noted also that plants having essentially the vegetative 
character of F. vesiculosus spiralis were found by the senioor writer at Quahog 
Bay, Sebascodegan Island, Maine, in August 1911. These plants were attached 
and bore well-developed receptacles. The occurrence of fertile plants in these 
colder waters in summer suggests that the plants at Cold Spring Harbor may 
be fertile during the winter. But it seems hard to believe that no trace of the 
fertile branches should remain on July 1 or be initiated by late September. 
Unfortunately, no thorough search was made for them in April 1911. 
Ectocarpus is the only other brown alga recorded in this belt between 1.5 
and 6.5 feet on the natural shores of the harbor. It occurs sparsely and 
locally at 0 south by 670 east between the 5 and 6 foot levels. It is matted with 
Rhizoclonium at 35 south by 575 east. This is apparently identical with the 
Ectocarpus occurring in the deep part of the channel of the Creek about 150 
feet south of the last-mentioned locality. It is possible that the plants were 
simply broken-off portions floated by the water to the spots where they were 
found. But the filaments recorded seemed to be living and growing. 
RHODOPHYCES. 
The only red alge that have been found growing above the 1.5-foot level are 
Bostrychia rwularis, Delesseria leprieuru, Hildenbrandia prototypus, Petrocelis 
(cruenta?), and Porphyra lacimata. All of these except Porphyra have been 
recorded from among the Spartina of the Mid-littoral Marsh, but only Hilden- 
brandia is at all frequent in summer. 
Bostrychia rwularis, although abundant on the rocks and piles of the wharves 
at all seasons, has been found in the Spartina marsh but once. This was in 
September 1911, when a patch of several square decimeters was found growing 
on a sunken log among the Spartina just north of the wharf of the Research 
