460 BULLETIN OF THE BUREAU OF FISHERIES. 



(20) THE CHORDARIA ASSOCIATION. 



Chordaria flagelliformis during the summer develops extensive growths on stones 

 and rocks a little below low-water mark. It grows in large masses and is frequently 

 the most conspicuous member of the zone of brown alga?, fringing exposed rocks near 

 low- water mark. The other prominent members of this zone are commonly Phyllitis 

 fascia and Scytosiphon lomentarius, which grow above the Chordaria and in the littoral 

 region. The Chordaria is frequently overgrown with Ectocarpus confervoides , E. 

 fasiculatus or E. siliculosus , and it also harbors Calliihamnion Baileyi, C. corymbosum, 

 and other algal epiphytes. 



(21) THE MESOGLOIA ASSOCIATION. 



Mesogloia divaricata grows in masses on stones and algae in relatively quiet waters 

 a little below low-water mark. It is a conspicuous summer plant occupying a situation 

 somewhat similar to that of Chordaria flagelliformis in more exposed situations. 



(22) THE RALFSIA ASSOCIATIONS. 



Ralfsia clavata is very abundant on stones and shells at low-water mark and below. 

 It is widely distributed throughout the sublittoral region at Woods Hole and in the Bay 

 and Sound, and has been dredged in 3 to 12 fathoms. Ralfsia verrucosa is less widely 

 distributed, but in certain localities has been found in quantity (Grassy Ledge, Little 

 Harbor, Tarpaulin Cove) ; it grows on stones near low-water mark. 



(23) THE CHORDA ASSOCIATION. 



Chorda filum is a summer species very common in the sublittoral region on stones 

 and shells in water 3 feet or more in depth. It frequently forms large beds and some- 

 times supports extensive epiphytic growths of Ectocarpus fasiculatus, Ceramium rubrum, 

 and other species. Chorda filum is widely distributed throughout the Bay and Sound 

 (chart 234) and was dredged in 2 to 14 fathoms. 



Chorda tomentosa is a very beautiful spring species common at Woods Hole in the 

 same situation as Chorda filum, which takes its place later in the season. We know 

 nothing of its distribution in Buzzards Bay and Vineyard Sound. 



(24) THE LAMINARIA ASSOCIATIONS. 



The genus Laminaria has only three representatives in the waters of Buzzards 

 Bay and Vineyard Sound. In comparison with the flora north of Cape Cod the kelps 

 play but an insignificant part in the vegetation of this region. 



Laminaria A gardhii is rather widely distributed (chart 235) , being common at Woods 

 Hole on wharves and stones in water 3 feet or more in depth ; it was dredged over sandy, 

 shelly, and stony bottoms in 2 to 17 fathoms. 



Laminaria Agardhii var. vittala is restricted in its distribution chiefly to the lower 

 portion of the Bay and westerly portion of the Sound (chart 236) ; it grows over sandy, 

 shelly, and stony bottoms in 2 to 17 fathoms, sometimes forming beds of considerable 

 extent frequently mixed with Laminaria Agardhii. 



