FAUXA OF THF ISLES OF SCILLY. 129 



broadcast along the foreshores ; and where the groimd was at all 

 soft, these stones were usually so deeply imbedded in tlie sand, 

 that only about one in twenty could be turned over. Owino- to 

 the extreme hardness of this granite, there were no rock pools to 

 be found within tidal limits. In the most sheltered coyes sand- 

 banks were present, and here the Zostera flourished, the tangled 

 roots effectually binding the sand together. In Forth Cressa bay, 

 by far the best collecting ground, there is an outer fringe of 

 granite boulders which form a natuial break-water, and in some 

 measure protect the foresh(n'es from the action of the wayes. 

 Here the littoral fauna is good, and a representatiye collection 

 can be made especially during spring-tides. Possibly during the 

 time of Lewes' yisit in 1855 the season was more fayourable, and 

 many of the deeper-dwelling forms had come inshore for breeding 

 purposes, and so he was able to record the capture of such rare 

 nudibranchs as Eolis alba and Acfreon. 



I now pass on and giye a list of animals found along the 

 foreshores of St. Mary's island : — 



ACTINIA.. 



Anthea cereus. Common between tidal marks. 



Actinia iiu'seinhri/anthcmiim. Abundant eyerywhere. 

 Sagartia bcUis. Scarce, very locally distributed. 



Haliclystiis auricula. Two specimens low water spring- tide, 



Forth Cressa bay. 



HYDEOIDA. 



Campamilaria neglecta. On underside of a rock about low- 

 water mark. Forth Cressa bay. 



MOLLUSCA. 



Chiton ? Capsules very abundant on sea- weeds. 



Nassa reticulata. Common. Spawn abundant on Zostera. 



Trochus cinerarius. Common. 



T. ziziphimis. Scarce. 



T, niagus. Not common. 



Patella vulgata. Abundant everywhere. 



Scalaria communis. One specimen Forth Cressa bay. 



Cardium eduJe. Common ; specimens ^ery large indeed. 



