THE ALIMENTARY CANAL. 
81 
Fig. 45.— Anatomy of a Gasteropod (Snail): a , mouth; b, foot; c, anus; d, lung; e , 
stomach, covered above by the* salivary glands; /, intestine; < 7 , “liver”; h , heart; 
?, aorta; j, gastric artery; &, artery of the foot; l, hepatic artery; m, abdominal 
cavity, supplying the place of a venous sinus; n, irregular canal communicating 
with the abdominal cavity, and carrying the blood to the lung; 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. 42 
s l k r b 
Fig. 46.—Anatomy of a Lamellibranch ( Mactfa): a, shell; b , mantle; c, tentacles, or 
lips; d, mouth ; e , nerves ; /, muscles; g, anterior, and n, posterior ganglion ; h, 
“liver”; i, heart; k , stomach; l , intestine passing through the heart; m, kid¬ 
ney; o, anal end of the intestine ;jp, exhalent, and q, inhalent respiratory tubes, 
or siphons; r, gills; s, foot. 
6 
