HABITS OF THE CEPHALOPODA. 63 



The natation of the Poulpe does not at all resemble that of the 

 other cephalopods. To swim, the Poulpe raises its sack above 

 the arms, tills ii with water, and. at the moment that the water 

 leaves the funnel, suddenly closes its arms which are furnished 

 with a swimming web at their base. The movement of the 

 animal is thus very oblique, and it is also heavy and clumsy, as 

 being unused to that mode of locomotion.* 



Sepia officinalis. The use of the tentacular arms of the Sepias 

 was absolutely unknown to me until I had the satisfaction to see 

 them in motion on a morning of the month of August (18(57). 

 A case of the aquarium had contained for nearly a month a Sepia 

 of medium size, which, during that time, had taken no nourish- 

 ment. I threw to it a rather large-sized fish (Caranx), which 

 swam towards the retreat of the Sepia who had hardly per- 

 ceived it. when, wiih prodigious celeriiyand precision, he un- 

 rolled and launched forward his tentacular anus, seized the fish 

 and drew it towards his mouth. The tentacular arms then 

 retracted and disappeared, but the sessile arms wrapped them- 

 selves closely around the head and anterior portion of the body 

 of the unfortunate tish which never made a movement after it 

 was caught. The Sepia swam about easily in all directions for 

 about an hour, eating the while; it then let the remains of the 

 fish drop to the bottom of the aquarium, having opened the skull 

 and devoured the brain as well as a portion of the muscles of 

 the back. 



The use of the tentacular arms is then no longer doubtful ; 

 they serve for the seizure of food. I have been able to verifv 

 this fact a second time in examining the ( 1 alamaries which pur- 

 sued a troupe of little fishes, capturing them with these members. 

 Moderate forward or backward progression is not due solely to 

 the tins as 1 have previously stated, but is assisted by the ex- 

 pulsion of water from the funnel; if the animal move forward, 

 the funnel is recurved in front, and forms nearly a right-angle 

 with the body; in retrograde movement lhe siphon becomes 

 horizontal; it is placed to the right or left when the Sepia 

 would turn, and is strongly recurved from front to back when it 

 would mount; to the surface of the water. 



* Dr. Paul Fischer, Ann. des Sc. Nat., 5 ser., vi, 308^320, 1866. 



