216 W. C. ALLEE. 



many of the animals are to be found on the upper surface of the 

 rocks under the protecting rockweed. This association may be 

 designated as the protected rock association or more obviously 

 as the rockweed association. 



(i) Exposed Rock Association. — The association inhabiting the 

 exposed rocks was much studied at the opening of Northwest 

 Gutter into Buzzards Bay. The rocks are exposed to the full 

 sweep of the waves across the Bay and support a sparse growth 

 of Ascophyllum and Fucus. 



Similar conditions are common along the coast. They were 

 studied in three localities: (i) At the outer point of East Buck 

 Island in Lackey's Bay; this differs only in that submerged 

 vegetation lies closer to the rocks on the shore side and extends 

 around the rocks on the Sound side. The waves from the Sound 

 break freely over these rocks. (2) At Gansett on the point 

 which separates Gansett Bay from Quissett Harbor. The whole 

 bottom nearby is covered with eel-grass while in the immediate 

 vicinity Sargassum filipendula, Ascophyllum and Fucus grow in 

 abundance. These rocks are frequently reached by the direct 

 waves from Buzzards Bay and are themselves practically free of 

 rockweeds. (3) In the region of Southwest Gutter where the 

 rocks are protected from the sweep of the waves but are washed 

 by strong and almost constant tidal currents coming now from 

 the Sound and now from the Bay. The direction of the current 

 makes little difference in the character of the water since in 

 either case it passes through tortuous, shallow passages supporting 

 a large amount of submerged vegetation. While there are many 

 plants nearby, these rocks do not support a large amount of 

 plant life. Water analyses from this association are given in 

 Table V. 



The animals most common in the exposed rock association are 

 the sponges, Microcione and Cliona; the actinians, Sagartia 

 leucolena and lucicB and Metridium; the starfish, Asterias; the 

 annelids, Harmothoe, Hydroides, Leprcea and Lepidonotus; the 

 bryozoan Bugula and various incrusting forms; Balanus balan- 

 oides and eburneus, the barnacles; Chceto pleura, the chiton; the 

 bivalve molluscs, Anomia and Mytilus; the snails, Acmea, 

 Littorina litorea, Eupleura, Purpura and JJrosalpinx; and the 

 chordates, -Amarcecium, which is usually and characteristically 



