A Typical Bivalve Mollusk 



in the right valve. The mantle spreads over everything. It 

 lines each valve, and is attached to each along the pallial line. 

 Outside this it hangs free as a thickened frill. At the posterior 

 end of the body the two mantle edges unite to form two tubes. 



D 



PARTS OF HARD SHELL CLAM (Venus Mercenaria) 



A, anterior end 



P, posterior end 



D, dorsal side 



V, ventral side 



es, excurrent siphon 



is, incurrent siphon 



ig, inner gill 



og, outer gill 



n, gill chamber 



a, a, adductor muscle scat 



6, beak or umbo 



c, hinge teeth 



/, hinge ligament 



/, /, labial palpi 



/, foot 



0, border of mantle 



J, shell border 



Ab, limule 



Through one, the incurrent siphon, water passes into the mantle 

 chamber. Through the other, the excurrent siphon, water is 

 discharged. When withdrawn these tubes occupy the pallial 

 sinus. The siphons are always behind. 



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