58 HABITS OF THE CEPHALOPODA. 



head with the trunk. The tentacular arms remain contracted 

 within the others when in repose; a position ditlicult to under- 

 stand, 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 antenniie, the others pre- 

 serving their normal attitude ; sometimes, also, the fourth pair 

 of arms droj) towards the earth for a few moments, and much 

 elongate themselves. 



The coloring of the Sejiia is eminently varia])le ; 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. Tiie eye is fatigued in fol- 

 lowing the incessant variation of coloring caused by the constant 

 movement of the pigment (;ells, and the metallic reflections of 

 the head and arms are glorious beyond human skill to reproduce. 

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

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

 This is accompanied by 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 strii)ed bands. The apiuoach of 

 death is e(pially announced l)y a change of colors, wliich grow 

 dull. 



The swimming of the Sepia is dilferently effected, according to 

 the sjjeed re(iuired. A moderate progression is equally easy 

 forwards or backwards. When the animal moves forward, the 

 body remains horizontal ; the tentacles, united and extended in 

 front, rest on the fourth i)air of arms, 'i'he Sepia follows in this 

 manner the course of the Avater, the resistance of which bends 

 the extremities of the united arms. A moderate backward move- 

 ment is effected in the same manner ; Init the tentacles are more 

 elongated and their extremities are somewhat parted ; the arms 

 are raised to the line of the body. The undulations of the fins 

 commence at the front or rear, according to the direction which 

 the animal takes. This method of swimming, due entirely to the 

 lins, is not slow, for the normal movement of the Sepia is easy, 

 elegant and rapid ; but an occasion of disquietude, as the sight of 



