CEPHALOPODA. 213 



thus locked together, have more power in holding 

 struggling prey, than they could have separately and 

 singly : a structure that art has endeavoured to imi- 

 tate, in the formation of a valuable and effective 

 surgical implement. Some species of this genus 

 attain a vast size : one, which was found dead by 

 Sir Joseph Banks in one of the Polynesian Islands, 

 must have measured six feet in length. The natives 

 of those islands live in great dread of them. 



Sepia* the Cuttle. 



With the two long feet in addition to the eight 

 arms, which characterize the Loligo, the Cuttle has 

 a rounder and more robust figure, and is furnished 

 with a fleshy fin, running down the whole of each 

 side. The plate is hard and shelly in its texture, 

 but one side is composed of exceedingly delicate 

 layers of shelly matter, standing up perpendicularly 

 to the plate, at some little distance from each other, 

 and kept apart by innumerable little pillars, invisible 

 without the aid of a microscope. In consequence of 

 this structure, it is so light, as to contribute to the 

 buoyancy of the animal in water. The form of 

 the whole is oval, and slightly convex on both sur- 

 faces. It is chiefly used to polish the soft metals : 

 the eggs of the Cuttle are frequently found cast 

 on shore, or fastened to sea-weeds, or rocks : they 

 are often called sea-grapes : and, indeed, it is no 

 unapt comparison, for they much resemble a clus- 



* Its ancient name with the Greeks. 



