BIOLOGICAL SURVEY OF WOODS HOLE AND VICINITY. 



471 



Castagnea virescens. 

 *Chordaria flagelliformis. 

 *Leathesia diffonnis. 

 *Mesogloia divaricata. 

 *Ralfsia clavata. 

 *Chorda filum. 



Laminaria Agardhii. 



Laminaria Agardhii var. vit 

 tata (o). 



Antithamnion americanum (o). 



Callithamnion Baileyi. 



C. byssoideum. 



C. corymbosum. 

 *Ceramium rubrum. 

 *C. strictum. 

 *Griffithsia Bornetiana. 



*Chondria tenuissima. 



C. tenuissima var. Baileyana. 

 *Dasy& elegans. 



Polysiphonia elongata. 



P. fastigiata (o). 

 *P. nigrescens. 

 *P. variegata. 

 *P. violacea. 



Actinococcus subcutaneus. 



Ahnfeldtia plicata. 

 *Chondrus crispus. 

 *Phyllophora Brodiasi. 



P. Brodiaei var. catenata (o). 

 *P. membranifolia. 



Sterrocolax decipiens (o). 



*Agardhiella tenera. 



Cystoclonium purpurascens. 



C. purpurascens var. cirrho- 



sum (o). 

 *Champia parvula. 

 *Lomentaria uncinata. 



Rhodymenia palmata (o). 

 *Grinnellia americana. 



Gloiosiphonia capillaris (o). 



Polyides rotundus. 



Corallina officinalis. 



Hildenbrandia prototypus. 



Melobesia farinosa. 



M. membranacea (o). 



M. pustulata. 



The warm-water sublittoral formation of the summer is known not only from the 

 dredgings in the deeper waters, but also from many observations in the shallow waters 

 at a number of points at or near Woods Hole, where the algal flora along shore has 

 been studied by the writer for some ten summers. Extensive studies along shore have 

 not been possible in the regions of the cool-water subUttoral formation (that is, in the 

 lower portion of Buzzards Bay and westerly portion of Vineyard Sound), and the flora 

 of the shallow water is known only at a few points, such as Gay Head, portions of Cutty- 

 hunk, and Penikese. 



It is interesting to note that a considerable number of species in the above lists are 

 restricted wholly or largely to shallow water in a zone from low-water mark to a depth 

 of 3 to 6 feet. The characteristic algae in this zone of the upper warm-water sublittoral 

 are: 



Chaetomorpha linum. 

 Cladophora, the species in the 



above lists. 

 Ectocarpus, the species in the 



above lists. 

 Pylaiella littoralis. 

 Sphacelaria cirrhosum. 

 S. radicans. 

 Punctaria plantiginea. 

 Castagnea virescens. 

 Chordaria flagelliformis. 



Leathesia diffonnis. 



Mesogloia divaricata. 



Ralfsia clavata. 



Chorda filum. 



Callithamnion Baileyi. 



C. Baileyi var. laxum. 



Ceramium rubrum. 



Chondria dasyphylla. 



C. sedifolia. 



C. tenuissima. 



C. tenuissima var. Baileyana. 



Polysiphonia fastigiata. 



P. fibrillosa. 



P. variegata. 



P. violacea. 



Chondrus crispus. 



Champia parvula. 



Lomentaria uncinata. 



Grinnellia americana (on piles). 



Melobesia farinosa. 



M. pustulata. 



The algae listed in the Zostera formation (c) may also properly be included in this, 

 the upper warm-water sublittoral formation. 



The summer temperature of the water is undoubtedly the chief factor in determining 

 the warm-water sublittoral formation as a whole. The degree of exposure to wave action 

 or tide currents and the character of the attachment are of course important factors 

 affecting the local distribution of the algae along the shores. Thus, the vegetation off 

 exposed points, as at Nobska or on the ledges in the passage of Woods Hole, is subjected 

 to conditions very different from those of neighboring sheltered coves. As stated before, 

 the summer temperature in Great Harbor, Woods Hole (as shown by daily averages 



