PHYSIOLOGY OF THE INVERTEBRATA. 71 



Fig. 19. — Alimentary Canal op Helix aspeesa. 



A. a = mouth. t = odontophore. c = tooth. d = buccal mass. 

 e = cesophagusv /= salivary duct, g = salivary gland. A = rectum, 

 i = crop or proventriculus. & = intestine. / = liver, m = stomach, 



B. Buccal Mass. a — tentacle (optic organ), b = tentacle (olfactory 

 organ ?). c = horny jaw. d = mouth, e = lateral lip. / = cir- 

 cular lip. 



C. Longitudinal Section of Buccal Mass. a = odontophore. i = ra- 

 dular membrane, c = odontophore cartilage, d = intrinsic muscle. 



