BIOLOGICAL SURVEY OF WOODS HOLE AND VICINITY. 465 
ber of the cool-water sublittoral formation; it was dredged in the summer in the lower 
portion of Buzzards Bay in 2 to 19 fathoms. 
Polystphonia variegata is common in the summer on stones, Zostera, and larger 
alge, and also grows loosely attached over sand and mud in sheltered situations; it 
was dredged in 3 to 6 fathoms in the upper portion of Buzzards Bay (chart 248). The 
species belongs to the warm-water sublittoral formation, preferring sheltered situations. 
Polysiphonia violacea is abundant in the summer on stones, rocks, and on the larger 
alge below low-water mark; it was dredged in 1 to 13 fathoms over sandy and stony 
bottoms and has a wide though scattered distribution in the Bay and Sound. ‘The 
species is an important member of the zone of red alge below low-water mark on rocks 
in exposed situations, taking the place which P. urceolata occupies in the spring. It 
belongs to the warm-water sublittoral formation. 
(42) THE RHODOMELA ASSOCIATIONS. 
Rhodomela Rochei and R. subjusca are probably very abundant in the spring through- 
out the Bay and Sound. The bases of old plants were dredged during the summer 
at scattered stations in 3 to 8 fathoms for Rhodomela Rochet, and 3 to 12 fathoms for 
R. subfusca. In the spring these species are undoubtedly conspicuous members of 
the cool-water sublittoral formation (A). 
(43) THE AHNFELDTIA ASSOCIATION. 
Ahnfeldtia plicata is common in exposed situations as off Gay Head and Cutty- 
hunk (chart 249). It was dredged in 1 to 14 fathoms (most plentiful in 7 to 13 
fathoms) over sandy, shelly, and stony bottoms, and is one of the cool-water sublittoral 
species. 
(44) THE CHONDRUS ASSOCIATION. 
Chondrus crispus, the Irish moss, is abundant along the shores of the Bay and 
Sound below low-water mark; it was dredged in 1 to 19 fathoms (most plentiful in 
4 to 12 fathoms) over sandy, shelly, and stony bottoms. The species is widely dis- 
tributed through the Bay and Sound (chart 250), wherever the bottom is favorable, 
and grows in dense patches on the rocks. It does not as a rule come so close to the 
surface as Ceramium rubrum, Polysiphonia fibrillosa, P. urceolaia, and P. violacea, 
but it is the most conspicuous member on exposed rocks of the zone of red algze some- 
what below these species. Chondrus crispus is a very important member of both 
the cool and warm-water sublittoral formations, with preferences for the former; for, 
although enduring the warm water of the summer, it grows. most luxuriantly in colder 
temperatures. 
(45) THE PHYLLOPHORA ASSOCIATIONS. 
The two species of Phyllophora have very similar life habits; they are rarely found 
in the upper level of the sublittoral region and are generally present only at a considerable 
depth. 
Phyllophora Brodiei grows on stones and in sand and mud and was dredged in 
1¥% to 15 fathoms (most plentiful in 4 to 1o fathoms). It is distributed very generally 
39 
16269°—Bull. 31, pt 1—13 
