134 MOLLUSCA. 



7. The eyes, pigmented spots on the outer edges of the ten- 

 tacles. 



8. The proboscis, which, when extended, protrudes from 

 beneath the portion that bears the tentacles. What is its size, 

 shape, and general appearance? It may be retracted entirely 

 into the body. 



9. The mouth, at the end of the proboscis. The end of 

 the odontophore may frequently be seen protruding from the 

 mouth. 



10. The foot What is its position, consistency, color, and 

 shape? Is it slimy? Determine by cutting thin sections which 

 regions of the foot are ciliated. 



11. The opening of the pedal gland, on the sole of the foot. 

 Is the pedal gland well developed in both sexes? Do you know 

 its function? (See Buccinum by Dakin, 1912.) 



12. The operculum. Notice its position and attachment. 



13. If the specimen is a male, the large, somewhat flattened 

 and bent penis, a little to the right and posterior to the right ten- 

 tacle. 



A number of organs may be seen through the somewhat 

 transparent mantle. These are: 



14. The liver, which forms the first two whorls of the spire 

 Notice its color. 



15. The gonad, which is borne on the dorsal surface of the 

 liver, and differs in individuals from red and brown to yellow. 



16. The stomach, which lies on the left (external) surface of 

 the liver. It is curved and light colored and is frequently rather 

 indistinct. 



17. The kidney, which lies on the dorsal surface, and a little 

 to the left side, on the anterior end of the liver. It is somewhat 

 rectangular in shape and differs in color from a yellowish-brown 

 to a chocolate color. The kidney is composed of two parts, 

 the large acinous portion, and the smaller tubuliferou^ portion. 

 The latter lies along the left side of the former, by the side of 

 the pericardium. 



18. The pericardium lies to the left of the anterior end of 



