BUSYCON 145 



Before beginning the dissection, note the following parts: 



1. The visceral dome. The portion that extended into the 

 spire of the shell. 



2. The mantle, which is thin and closely applied to the 

 visceral dome, and raised to form a thickened collar that 

 extends entirely around the body along a line that corresponds 

 to the aperture of the shell. 



3. The siphon, which is a spoutlike prolongation of the 

 collar. Into what portion of the shell does it fit? 



4. The mantle chamber. This can be seen by raising the 

 edge of the collar of the mantle. 



5. The head, which forms an anterior prolongation. 



6. The tentacles, forming two triangular projections on 

 the head. 



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

 tentacles. 



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? 



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 flat- 

 tened and bent penis, a little to the right and posterior to the 

 right tentacle. 



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. 



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