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EVOLUTION OF ANIMALS 



Part V 



ventricle 



anterior 

 retrac 



anus 



adductor 

 muscle 



ige 

 mantle 



liver 



testis 



ovary 



oce 



kidney 



adductor 

 mooth) muscle 



nus 



or 

 sole 



Fig. 31.9. Upper, general structure of the salt water littleneck or quahog {Venus 

 mercenaria) . The left shell, part of the mantle and the gills are cut away. Lower, 

 general structure of the scallop (oyster), Pecten. The adductor muscle that pulls 

 the shells together is familiar as fried scallop. The brilliant blue eyes are located 

 along the borders of the mantle. A scallop jumps through the water by clapping its 

 shells together, forcing out the water between them and flying forth, hinge forward, 

 actually jet propelled. 



