176 BIVALVES. 



sudden leap. In this manner it reaches the sea ; 

 should the weather be calm, it raises one of its 

 valves, which catching the breeze, acts as a kind 

 of sail, while the other resting on the surface, 

 supports the floating animal; when danger 

 threatens, the shell is closed, and sinks securely 

 to the bottom of the sea. Many of the Pectens 

 possess the power of forming threads, by which 

 they anchor themselves to floating timber, and 

 by this means find protection, when the sea is 

 agitated by storms and tempests. These varied 

 means of escaping danger are no doubt afforded 

 as a necessary protection against their numerous 

 enemies. The pilgrims who in former days 

 visited Jerusalem, to pay their devotions at the 

 holy sepulchre, on their return wore these shells 

 in their caps as trophies of their achievement in 

 crossing the seas for this sacred purpose ; and 

 in commemoration of this superstitious act of 

 devotion, it was often granted them to have 

 ,Pectens engraved in their coats of arms, that a 

 record of their religious zeal might be handed 

 down to posterity. 



The second division of Ostrea, contains the 

 shells which resemble the common oyster ; they 

 differ from the Pectens as much in their habits as 

 in their appearance. They are reputed to be 

 some of the most sluggish of animals, and to 

 have very limited powers and faculties ; but whilst 

 we cannot fail to observe this destitution, we 

 trace the goodness of the Creator, who has 

 placed them in situations not exposed to danger, 

 and bestowed upon them an organization that 



