Lamarck's Genera of Shells. 255 



narrow ala. A free, cretaceous, spongy, opaque bone, enclosed in 

 the interior of the body, near the back. Mouth terminal, sur- 

 rounded by ten arms, furnished with suckers ; two of the arms pe- 

 dunculated, and longer than the others. 



The bone enclosed in the body of the sepia, is friable, light 

 whitish, oval, rather thick in the middle, thin and sharp at the 

 edges. It is composed, according to Cuvier, of thin laminae, in 

 the interstices of which are a multitude of small hollow columns, 

 perpendicular to the laminae. 



The sepise attain a considerable size ; some are nearly twd feet 

 long. The head, which, with the upper part of the body of the 

 animal, projects beyond the sac, has two large, very remarkable eyes, 

 placed at the sides, and which are the most perfect of those of any 

 of the invertebrated animals ; except that they have no eyelids, 

 they appear to be as perfect as the eyes of vertebrated animals. 

 The suckers at the summit of the long arms, serve to keep the ani- 

 mal stationary, whilst it seizes its prey with the shorter ones, which 

 are also furnished with suckers, and are conical, pointed, and ra- 

 ther compressed at the sides. The form of the suckers, when ex- 

 tended, is " nearly that of an acorn cup, with a deep circular car- 

 tilaginous ring, armed with small hooks, which is secured in o. thin 

 membrane, something transparent by the projection of a ledge, in- 

 vesting its whole circumference about the middle of its depth, and 

 not to be extracted without some force. 



" Each sucker is fastened by a tendinous stem to the arm of the 

 animal ; which stem, together with part of the membrane that is 

 below the circumference of the cartilaginous ring, rises into, and 

 fills its whole cavity, when the animal contracts the sucker for 

 action. In this state, whatever touches it, is first held by the mi- 

 nute hooks, which insinuate themselves betwixt the scales of its 

 prey, and then is drawn up to a closer adhesion, by the retraction 

 of the stem, and inferior part of the membrane, much in the same 

 manner as a sucker of wet leather sustains the weight of a small 

 stone*." The mouth of the sepia is situated at the summit of the 



* Needham ou the Calarnaiy, p. 22. 1743. 



