LOLIGO PEALII. 117 



2. The arrangement of the funnel. Why does it have a 

 thin posterior edge? How is it held in position against the 

 mantle? Does it have a valve? Is the siphon movable in the 

 living animal? 



3. The free edge of the mantle and its relation to the folds 

 beneath the eyes. Do you understand how the water gets into 

 and out of the mantle cavity? 



4. The large retractor muscles of the funnel. How many are 

 there? How can the funnel be pointed in different directions? 

 What need is there for such a provision ? 



5. The retractor muscles of the head. How many are there? 

 Are they used in swimming in any way? 



6. The rectum, opening near the base of the funnel between 

 two small lateral flaps of tissue. 



7. The ink-hag, dorsal to the rectum and opening into it 

 near the anus. 



8. The gills, extending from a point about midway of the 

 body toward the free edge of the mantle. How many are there? 

 How are they attached ? Why does an animal that is not swim- 

 ming continually pump water through the inantle chamber? 



9. The branchial hearts, at the bases of the gills, rounded, 

 light colored organs that can be seen through the membrane 

 covering them. 



10. The median ventral mesentery. 

 If the specimen is a male, notice: 



1. The slender, tapering penis, to the left of the rectum. 



2. The kidneys, white organs to be seen through the mem- 

 branous covering, between the bases of the gills. From this 

 position they taper anteriorly for half an inch or more and send 

 small lobes posteriorly. 



3. The openings of the kidne3^s near their anterior ends, on 

 small papillae. 



4. The conical posterior portion of the viscera. This is com- 

 posed of a large visceral sac and portions of the sexual organs. 



Draw the animal, showing the points observed. 

 If the animal is a female, notice: 



