SEPTID^. 41 



The chalky thickening of the shell is iised as a dentifrice,* and 

 also for modeling metallic objects, its surface receiving an 

 exceedingl}^ accurate impression. Ciittle-bone is a favorite beak- 

 sharpener for caged birds. 



The following observations on Sepia officinalis were made by 

 Dr. Paul Fischer, in August, 1866, at the aquarium of Arcachon, 

 Gironde, France. Besides the usual glass cases, there are here 

 vast basins with earth bottoms, and of moderate depth, which 

 receive the results of the fisher}^ on the shore itself. Without 

 this commodious arrangement, it would be impossible to preserve 

 living, the very delicate animals. 



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 ; alwaj^s shaded, the}'' 

 remain immobile in the horizontal position, nearlj^ touching the 

 earth by their ventral surface. After some days of repose, the}^ 

 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, forming 

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

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

 the trunk. The tentacular arms remain contracted within the 

 others when in repose; a position diflScult to understand, as after 

 death they are found to be more than double the length of the 

 sessile arms. Sometimes the first pair of arms are raised into a 

 vertical position, like antennae, the others preserving their normal 

 attitude ; sometimes, also, the fourth pair of arms drop towards 

 the earth for a few moments, and much elongate themselves. 



The coloring of the Sepia is eminently variable ; but if the day 

 is clear, the dorsal surface and arms are magnificently striped ; 

 the edges of the fins are black, and their superior face is orna- 

 mented with spots of the same color. On the back of large indi- 

 viduals is seen two large obscure spots, which vary in intensity 

 and sometimes entirely disappear. The e^^e is fatigued in fol- 

 lowing the incessant variation of coloring caused by the constant 

 movement of the pigment cells, and the metallic reflections of 

 the head and arms are glorious bej^ond lj.uman skill to reproduce. 

 The skin is usuallj^ smooth ; but when the animal becomes irri- 

 tated, it shows granulations, principally on the head and back. 

 This is accompanied hy a retraction of the arms, which appear 

 both shorter and narrower; the extremities no longer touch, but 

 curve slightly. At the same time the colors change, a uniform 

 gray tint takes the place of the striped bands. The approach of 



* This manufacture is extensively pvirsued at Liverpool ; as much as 13 

 cwt. of cuttle-bone arriving at one time for this purpose. 



