ventricle 



f pericardium 



rectum 



f 



/ kidney 



^_,--dorsal palltal aperture 

 -- posterior aorta 

 post, retractor 



post adductor 

 anus 



...... visceral ganglion 



exhalant si plum 

 super brcwichial e ham her 



- right gill 



inhalant 



* shell 



pal Hal groove 



mantle 



mantle cavity 

 Fresh-water mussel, I'nio sp. 



