CUTTLF^BONE. 363 



Generally, the animal throws out its ink on the least alarm, a circumstance of some 

 importance in geology. It was discovered by Dr. Buckland that in many specimens of 

 fossil cephalopods, called scientifically Geoteuthis, /. e. Earth Squid, the ink-bag remained 

 in the animal untouched by its long sojourn within the earth, and even retaining its 

 quality of rapid mixture with water. A drawing was actually made by Sir F. Chantrey, 

 with a portion of " sepia" taken from a fossil species, and the substance proved to be 

 such excellent quality that an artist, to whom the sketch was shown, was desirous of 

 learning the name of the colorman who prepared the tint. 



THE Belemnites, those curious cucumber-like fossils, popularly called Thunderbolts, 

 which are found in various strata, are now known to be the remains of ancient Cala- 

 maries, of which the entire animal, with its mantle, fins, ink-bag, siphon, eyes, and ten- 

 tacles, has been discovered. 



THE third, and largest figure in the engraving, represents the common SEPIA, whose 

 wonderful chalky " bone " is so frequently thrown on our shores after the death of the 

 animal in which it was developed. 



This so-called bone was formerly in great repute for various purposes, but is now 

 merely employed in the manufacture of pounce and dentifrice, for which latter purpose, 

 however, prepared chalk is quite as effectual, being indeed the same substance, though in 

 the form of powder. It is composed of a vast number of nearly horizontal layers, sup- 

 ported by innumerable little pillars or fibres of the same substance. If one of these shells 

 be snapped across, the structure will be well shown even to the naked eye, while with the 

 help of a common pocket-lens, even the minutest details can examined. The upper 

 coat will mostly scale off so as to show its smooth surface, while the successive ranges 

 of glittering pillars look like a copy of the Giant's Causeway in miniature, as the irreg- 

 ular fracture breaks up their ranked columns into deep caverns and bold projecting 

 rocks. A diagonal cut with a knife will farther expose the hard horizontal strata with 

 their myriad pillars ; but the method by which the structure exhibits itself in its greatest 

 beauty is to make a very thin transverse section, mount it in Canada balsam on a glass 

 slide for the microscope, and employ polarized light in its examination. 



In consequence of its peculiar formation, the cuttle-bone is extremely light when dry, 

 and admits so much air into the interstices that it swims easily in water. One of these 

 shells is seen in the illustration, lying on the ground near the Sepia. 



In the right-hand corner, and lying on the ground, is seen a group of dark oval bodies, 

 looking something like a bunch of purple grapes, and from this resemblance termed Sea 

 Grapes by the fishermen. These are the eggs of the Sepia, which may often be found on 

 the seashore, flung there by the retiring tide, and left to perish unless rescued by some 

 friendly hand. If these bunches of eggs be placed in a vessel of sea-water, and guarded 

 from danger, they may be seen daily changing in appearance,' until at last they burst 

 asunder and let loose the inmates on the world. Nothing can exceed the nonchalant 

 demeanor of the tiny creature not two minutes old. It deliberately makes the tour of its 

 glassy prison, examines every detail with minute attention, and having quite satisfied its 

 curiosity, poises itself for a moment just above the ground, blows out a circular hollow 

 in the sand with a sharp expulsion of water from the siphon, and settles quietly into the 

 bed thus prepared for it. 



The Sepia, as well as others of its family, is a terribly voracious creature, and is 

 consequently hated by the fishermen, who sometimes see the Cuttles busily at work on 

 the fishes that are hanging on their hooks, holding the bodies firmly in their arms, and 

 tearing away the flesh with astonishing quickness, as if they knew the shortness of their 

 tenure. Their vigilance is, however, not to be dulled by their appetite ; for although they 

 will hold on to the last moment, they are far too wary to allow themselves to be caught, 

 and as soon as the fatal net approaches, they cast off their animated grapnels, and dart 

 away swiftly from the threatened danger. 



BEFORE proceeding to another large group of cephalopods, it is needful to mention 

 the curious animals called, from the shape of their shell, Spiralidae. These singular 

 creatures from a distinct though very small family, containing only three species. 



