THE ALIMENTAKY CANAL. 



81 



Fio. 45.— Auatoiny of a Gasteropod \S7iail): a, muath; o, foot; e, anus; d, lun^; e^ 

 stomach, covered above by the sail vary glands; /, intestine; g, "liver"; h, heari; 

 i, aorta; j, gastric artery; k, avtery of the foot; I, hepatic artery; m, abdominal 

 cavity, eupplying the place of a venoue sinus ; n, irregular canal communicating , 

 with the abdomiual cavity, and carrying the blood to the luug ; o, vessel carry- 

 ing blood from the lung to the heart. 



by a narrow "pyloric" orifice, or valve, but is not so clearly 

 distinguished from the gullet, so that regurgitation is easy," 



Fig. 46.— Anatomy o£ a Lamellibrftnch {Mactra)'. a, shell; 6, mantle; c, teutaclee, or 

 lips ; d, mouth ; e, nerves ; /, muscles ; g, anterior, and n, posterior ganglion ; A, 

 *Miver"; J, heart; k, stomach; l^ intestine passing through the heart; m, kid- 

 ney; 0, anal end of the intestine ; j>, exhalent, and 9, iuhalcnt respiratory tubes, 

 or siphons; r, gills; s, foot 



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