HABITS OF MARINE ANIMALS 145 



the scallop detects the shadow of the passing skate 

 by means of several eyes arranged in a row along the 

 border of each mantle, just under the valves. In 

 \Pecten maximus, the bivalve under consideration, there 

 lire from eighty to one hundred and twenty of these 

 byes, and nothing is more beautiful hi marine life than 

 the two circular rows of eyes, sparkling like precious 

 jjewels. 



When photographing the scallop shown I had to be 

 very careful not to let my shadow fall on him, or he 

 ^would instantly have shut up, and I should then have 

 had to wait at least half an hour before he had again 



[fully opened. 



Next, as to how the scallop opens and shuts. The 

 Itwo valves work on a hinge, and when the pecten is at 

 rest these valves gape open. They are closed by the 

 contraction of a strong muscle which is attached to 

 each of them on their inner surface. 



There are several movements which the pecten is 

 able to perform. It may jerk itself back a few inches 

 from some irritating object, it may rise from the bottom 

 and swim in a characteristic manner (as if taking a 

 series of bites out of the water), and if in good health 

 it will always right itself in a few seconds or minutes 

 when turned over on its flat valve. 



It was my good fortune to meet Dr. Dakin, of 

 Liverpool University, who has made pecten a subject 

 of special study, and with his assistance I was able 

 to take a photograph of this act of turning over, and 



K 



