72 



JFir0t annual deport 



Epiphragmophora arrosa Gld. 

 A few specimens found on the cliffs at Arch Beach. 



Opalia insculpta Cpr. 



Scala hindsii Cpr. 



Only empty shells of these two species were taken, and these were 

 inhabited by hermit crabs. 



Littorina planaxis Phil. 



The commonest shell of the beach, found in great numbers adher- 

 ing to the rocks from those only wet by spray at high tide down to 

 rocks uncovered only at low tide. 



Littorina scutulata Gld. 

 Occurring with L. phma.ris, but far less common. 



Figure 36. Pomaulax undosus 



Cypraea spadicea Gray 

 Rare among the rocks between tides. 



Murex gemma Sby. 



Among the rocks between tides, not common, but the most com- 

 mon of the Muricidiv. 



Not common. 



Purpura nuttallii Con. 



Ocinebra gracillima Stearns 



Acanthina spirata Blv. 



Of the above two species, only shells inhabited by hermit crabs 

 were found. 



