482 BULLETIN OF THE BUREAU OF FISHERIES. 
Phyllophora Brodizi, 7656, many; 7663, 7672 and) Polysiphonia nigrescens, 7659, many; 7656, 7664, 
7673, few. 7666, 7668, and 7672, few. 
Phyllophora membranifolia, 7659 and 7662, many; | Polysiphonia urceolata, 7670, 7673, and 7675, few. 
7657, 7660, 7663 (1907), 7664, 7666, 7672 (1907), | Polysiphonia violacea, 7664, few. 
and 7675, few. Rhodomela subfusca, 7656 and 7667, few. 
Pleonosporium Borreri, 7675, few. Rhodymenia palmata, 7664, 7665, 7666, 7667, 7670, 
Polyides rotundus, 7659, many; 7660 and 7666, and 7671, few. 
few. Seirospora Griffithsiana, 7660, few. 
Polysiphonia elongata, 7656, 7662 (1907), 7665, and | Spyridia filamentosa, 7671, many; 7656 and 7675, 
7675, few. few. 
Summarizing this statement of the algal vegetation in Buzzards Bay, it may be said 
that the life conditions are much more favorable in the lower portions of the Bay than in 
the upper, since the bottom is generally stony and the water clearer, because silt and 
mud are less frequent. These characteristics are graphically shown on chart 227, and 
it will be noted that the greater part of Buzzards Bay has a muddy bottom. Such 
regions in the deeper waters are almost deserts as regards vegetation. The algal flora 
of the upper portion of Buzzards Bay is, in the summer, composed of species character- 
istic of the warm-water sublittoral formation, which also extends somewhat into the 
lower portions of the Bay. However, the vegetation changes markedly toward the 
entrance of the Bay, both as to its characteristics and its quantity, as is shown by 
the above lists. Species appear which are peculiar to the cool-water sublittoral forma- 
tion. Around the exposed reefs of Sow and Pigs the vegetation is typical of this forma- 
tion, which is presented in even greater luxuriance off Gay Head. 
2. THE MIDDLE REGIONS OF VINEYARD SOUND. 
The conditions in Vineyard Sound differ from those of Buzzards Bay in several 
respects. The tides which flow east with the flood and west with the ebb have a 
velocity of 1 to 3 knots an hour, which is so strong a current that extensive deposits 
of mud or fine silt are generally rendered impossible. The bottom is in consequence 
chiefly hard sand, frequently mixed with shell fragments, gravel, or stones. There is 
little or no mud in the middle regions of the Sound. The average depth is somewhat 
greater than that of the Bay, but not enough to be an important factor in determining 
the character of the vegetation. There are no large areas of shallows under 6 fathoms, 
as are found in the upper portion of Buzzards Bay, the Middle Ground being the only 
extensive region of shoal water, and that is composed chiefly of sand and is quite barren 
of vegetation. 
Vineyard Sound within the limits of this Survey (that is, from a line drawn between 
the westerly end of Cuttyhunk and Gay Head to a line between Falmouth Heights and 
East Chop) has for convenience been divided into three regions as follows: (a) The 
westerly portion from the entrance to a line between the west end of Naushon (Robinsons 
Hole) and Kopeecon Point (Cape Higgon), (6) the narrow portion of the Sound between 
Naushon and Marthas Vineyard to a line connecting Nobska Point and West Chop, and 
(c) the easterly portion of the Sound from the last line to one between Falmouth Heights 
and East Chop. 
The westerly portion of Vineyard Sound includes large areas with a bottom of hard 
sand or sand with shell fragments, but exceptions to these conditions were found at a 
