THE ALIMENTARY CANAL 



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FIG. 243. Anatomy of a Gastropod (Snail): a, mouth; b, foot; c, anus; d, lung; e, 

 stomach, covered above by the salivary glands; f, intestine; g, "liver"; h, heart; 

 f, aorta; j, gastric artery; k, artery of the foot; /, hepatic artery: m t abdominal 

 cavity, supplying the place of a venous sinus; , irregular canal communicating 

 with the abdominal cavity, and carrying the blood to the lung; o, Vessel carrying 

 blood from the lung to the heart. 



q 



FIG. 244. Anatomy of a Lamellibranch (Mactra): a, shell; b, mantle; c, tentacles, or 

 lips; d, mouth; e, nerves; f, muscles; g, anterior, and n, posterior ganglion; k, 

 "liver"; z', heart; k, stomach; /, intestine passing through the heart; m, kidney; 

 0, anal end of the intestine; /, exhalent, and q, inhalent respiratory tubes, or 

 siphons; r, gills; s, foot. 



