UMAX MAXIMUS LINN.EUS 229 



drawing showing all organs in situ: immediately behind the 

 anterior tentacles the ovoid pharynx and above it two thin 

 tentacular nerves; at each side of the pharynx a dark band 

 the retractors of the second tentacles; behind these a coiled tube 

 passing to the right under the right retractor the penis with 

 its retractor the end of which is now free, since it has been cut; 

 on the left side and behind the penis the two white salivary 

 glands and the anterior end of the thin- walled stomach; the 

 brown-lobed liver with two loops of the intestine imbedded in it; 

 three long organs behind the salivary gland and to the right of 

 the liver the cephalic artery, oviduct and common retractor 

 of the tentacles; the aorta; at the extreme end the hermaphro- 

 ditic gland; at each side of the visceral mass running along the 

 foot the right and left pedal nerves; the flat rectum, its end dis- 

 appearing in the mantle cavity; in front of it, protruding through 

 the wall of the mantle cavity the cut proximal end of the 

 aorta; to the right of the rectum the cut attachment of the 

 common retractor of the tentacles and in front of this that of 

 the penis. 



4. Pull the retractor communis tentaculorum from beneath 

 the intestine. Free the hermaphroditic gland and canal. Cut 

 the liver blood-vessel. Free the intestine from the liver and 

 stomach without tearing any ducts or parts and leave it on your 

 left. Cut the retractor of the right tentacle and free the entire 

 reproductive system, pushing it to the right. Make a full page 

 drawing showing digestive and reproductive organs. In the 

 former, label: pharynx, ducts of salivary glands, oesophagus, 

 salivary glands, stomach, liver, intestine and rectum. In the 

 reproductive system, label: retractor penis, penis, vas deferens, 

 vas efferens, bursa copulatrix, vagina, oviduct, albuminous 

 gland, hermaphroditic duct, and hermaphroditic gland. 



5. Remove the digestive and reproductive organs. Open the 

 mantle cavity by carefully removing with a forceps the body 

 wall below it. Make a drawing showing nervous, circulatory 

 ard excretory systems. Label anus, pneumostoma, rectum, 



