HABITS OF THE CEPHALOPODA. 57 



It is altogether probable that pelagic cephalopoda, highly or- 

 ganized, with powerful locomotive apparatus, and frequently 

 attaining great size and strength, may enjoy a distribution fully 

 equal to that of the littoral species: such is known to be the 

 case in some species which, normally circumboreal in distribu- 

 tion, are found nevertheless extending into temperate latitudes 

 in both oceans. 



Habits of the Cephalopoda. 



I. Observations on certain points in the natural history of the Cephalo- 

 pocls. By Dr. Paul Fischer. 



It is difficult to study the cephalopods in the living state. 

 Most of them, accustomed to move freely in space, will not 

 accustom themselves to the straightened limits of the aquarium; 

 besides the discharge of ink. made upon the slightest disturb- 

 ance, discolors and obscures the water for entire hours. Except 

 some good figures of Poulpes, there are no really good repre- 

 sentations of these animals, because they have always been 

 made from dead specimens. 



The observations recorded were made in August, 1866. at the 

 aquarium of Arcachon, (lironde, France. Besides the usual 

 glass cases, there are here vast basins with earth bottoms, and 

 of moderate depth, which receive the results of the fishery on 

 the shore itself. Without this commodious arrangement, it 

 would be impossible to preserve living, the very delicate 

 animals. 



Sepia officinalis. The fishermen gather the young individuals, 

 called Casserons, for food. When caught for the aquarium, they 

 are at first placed in the great basins ; they show themselves 

 very timid, discharge inky clouds, and hide under floating 

 objects; always shaded, they remain immobile in the horizontal 

 position, nearly touching the earth by their ventral surface. 

 After some days of repose, they are transferred to a glass 

 aquarium. 



The normal position of the Sepia is horizontal, the fins undu- 

 lating gently, the sessile arms joined at their extremities, form- 

 ing a sort of pyramid or tetrahedon. In this position the 

 appearance of the head and arms is very like that of an elephant's 



