490 BULLETIN OF THE BUREAU OF FISHERIES. 
The main channel near Hadley Rock (station 121) has a bottom of sand and stones. 
There was an abundance of Laminaria A gardhiti, Agardhiella tenera, Chondrus crispus, and 
Gracilaria multipartita, together with a few plants of Sargassum Filipendula. Dredgings 
of previous years have shown that Callithamnion rosewm grows on shells in the narrower 
portion of the passage (Woods Hole proper), and also Scinaza jurcellata. ‘The passage on 
the south is bordered by ledges, chiefly submerged, and these are covered with heavy 
growths of alge. The reader may obtain a general idea of the character of the algal 
life on these rocks bordering the channel from chapter Iv, page 476, ‘“‘A Report on the 
Algee of Spindle Rocks, Woods Hole Harbor,” a small group of rocks (destroyed in the 
summer of 1905) that formerly lay between Grassy Ledge and Red Ledge. These sub- 
merged ledges are difficult to study, but detailed examinations of some of them carried 
on through various seasons of the year would undoubtedly give some interesting results. 
The algal life on the bottom of the harbor of Woods Hole and in the two ships’ chan- 
nels that lead into it from Vineyard Sound on either side of Great Ledge is very sparse. 
The bottom is hard sand and sandy mud, unfavorable for extensive growths of alge. 
A haul (station 4) inside of Great Ledge in 2 to 5 fathoms over a sandy bottom gave a few 
plants of Antithamnion cruciatum, Ceramium rubrum, Chondrus crispus, Gracilaria mulit- 
partita, Grinnellia americana, Melobesia Lejolisi1 (on Zostera), and Phyllophora Brodier. 
(4) ROBINSONS HOLE. 
Robinsons Hole, along the west end of Naushon (stations 20, 21 and 22), has a 
rich algal flora over a stony bottom in 2 to 3% fathoms. There was an abundance of: 
Chorda filum, 21 and 22. Cystoclonium purpurascens var. cirrhosum, 20 
Desmarestia aculeata, 20, 21 and 22. and 22. 
Desmarestia viridis, 20 and 22. Hildenbrandia prototypus, 21 and 22. 
Laminaria Agardii var. vittata, 21. Lithothamnion polymorphum, 21. 
Antithamnion cruciatum, 22. Phyllophora Brodizi, 20, 21 and 22. 
Ceramium fastigiatum, 20. Phyllophora membranifolia, 22. 
Ceramium rubrum, 20, 21 and 22. Rhodymenia palmata, 21 and 22. 
Chondrus crispus, 20, 21 and 22. Scinaia furcellata, 21. 
Cystoclonium purpurascens, 20 and 22. Spermothamnion Turneri, 20 
In small quantities were found: 
Cladophora gracilis, 20 and 21. Ceramium strictum, 20. 
Cladostephus verticillatus, 21. Champia parvula, 20, 21 and 22. 
Ectocarpus siliculosus, 21. Corallina officinalis, 20 and 21. 
Laminaria Agardhii, 22. Dasya elegans, 21. 
Leathesia difformis, 20. Lomentaria uncinata, 21 and 22. 
Phyllitis fascia, 22. Polysiphonia fibrillosa, 20. 
Ahnfeldtia plicata, 21 and 22. Polysiphonia nigrescens, 20 and 22. 
Station 23, off the island of Pasque, at the entrance to Robinsons Hole, showed the 
presence of much Antithamnion cruciatum, Chondrus crispus, Phyllophora membrant- 
jolia, Rhodymenia palmata, and a few plants of Desmarestia aculeata, Desmarestia viridis, 
and Polysiphoma elongata. 
This flora has a mixed composition including forms characteristic of both the cool- 
and warm-water sublittoral formations, indicating that the summer conditions of Robin- 
sons Hole are somewhat midway between those of the open and those of tne sheltered 
waters of the Sound and Bay. 
