340 MOLLUSCA. 



surface, and as it has been even asserted that the germ of this shell has been seen in the egg of the 

 Argonaut *, we must say that this opinion is, to say the most of it, still very problematical. — Poll, 

 Testae. Neap. iii. p. 10. See also Ferussac, Mem. de la Soc. d'Hist. Nat. de Paris, ii. p. 160 ; and 

 Ranzani, Mem. di Star. Nat. Lee. 1. p. 85. It is the Nautilus and Pompilus of the ancients. — Plin. ix. c. 29. 



We know some species, very like each other both in the animal and shell, which Linnaeus confounded together 

 under the name of Argonauta nr(jo, vulgarly called the Paper-nautilus. 



It is supposed that we must ascribe to an animal analogous to the Argonaut, the Bellerophon, — fossil shells 

 rolled up spirally and symmetrically, and without septa; but thick, not grooved, and whose last whorl is propor- 

 tionably shorter. [Sowerby says that Bellerophon is the only fossil that bears any real resemblance to Argonauta, 

 but neither shell, in his opinion, has been formed by a Ceiihalopodous animal, but probably by one nearly like 

 that of Carinaria. The fossils are characteristic of the carboniferous limestone, and the oldest secondary strata : 

 in these the shell is frequently found changed to silex.] 



The Sleeve-fish {Lol/go, Lam.) — 

 Have in the back, instead of a shell, a horny lamina in the sliape of a sword or lancet. Their sac has 

 two fins ; and besides the eight feet, furnished with small pedicled suckers inordinately arranged, their 

 head supports two arms much longer than the feet, and only acetibuleferous near the ends, which are 

 enlarged. These the animal employs as anchors to fix itself. Their ink-bag is buried in the liver; 

 and the glands of their oviducts are very large. They lay their eggs attached together in straight 

 garlands, and in two series ; [and the entire mass somewhat resembles a mop, being composed of 

 numerous intestine-like filaments tied together in the centre]. 



The family is now subdivided from the number and armature of the feet, and the form of the fins. The Loli- 

 ffopsis, like the Octoinis, has only eight feet, but our knowledge of the genus rests upon figures that are scarcely 

 trustworthy. t In Loligo properly so called, the arms have suckers as well as the feet, and the tins are situated 

 towards the end of the sac. We have three species in our seas,— the L. vulgaris (Sepia loligo, Linn.) ; L. sagittata, 

 and L. subulata, or Sepia media, Linn. The Onycltotheuthis, Lichenst. (Onykia, Lesueur,) have the form of the 

 Loligo, but the suckers of their arms end in hooked spines. The Sepiola have rounded fins, attached, not to the 

 end, but to the sides of the sac. The common Sepiola (Sepia sepiola, Linn.) occurs in our seas. The body is short 

 and obtuse, with small circular fins. It never exceeds three inches in length ; and its horny lamina is slender and 

 jiointed like a needle. $ The Sepiotheutes, Blainv. (Choudrosepia, Leukard,) have the sac margined throughout 

 with the fins, as in the Sepia; but their shell is horny, as in the Loligo. 



The Cuttle-fish, strictly so called (Sepia, Lam.), — 

 Possess the two long arms of Loligo, and a fleshy fin stretched along each side of their sac. Their 

 shell is oval, thick, tumid, and composed of an infinity of very thin parallel calcareous laminae, joined 

 together by tliousands of little hollow columns, which are placed upriglil in the spaces between every 

 two laminae. This siructine renders it friable, whence it is employed by artists in polishing various 

 works ; and it is given to cage birds to sharpen their beaks upon. The Sepia have the ink-bag separate 

 from the liver, and situated deeper in the abdomen. The glands of the oviducts are enormously large. 

 They deposit their eggs attached to one another in branched clusters, not 

 unlike a cluster of grapes, whence the vulgar have called them Sea-grapes. 



The species distributed in all our seas (Sepia offieinalis, Linn.) reaches a foot or 

 more in length. Its skin is smooth, whitish, and dotted with red. In the Indian 

 Ocean there is one with a skin roughened with tubercles (S. fuberculata. Lam.). 



(Among fossils we find some little bodies armed with a spine, which are the 

 ends of a bone of Sepiai. They constitute the genus Beloptera of Deshayes. See 

 Ann. des. Se. Nat. ii. xx. 1,2. Some other fossils, but petrified, appear to have great 

 relation to the beaks of the Sepi*. These are the Ri/ncliolitliesof M. Faure Biguet. 

 —See Gaillardot, Ann. Sc. Nat. ii. 485, and pi. xxii. ; and D'Orbigny, ib. pi. vi.) 



Linnffius united in one genus — his pii, i5:._k^i;s of u.e Argonaui. 



Nautilus — 

 All spirally twisted, symmetrical, and chambered shells, — that is to say, divided by partitions into 

 several cavities ; and he supposed them to be inhabited by Cephalopods. One of them is, in fact, the 

 shell of a Cephalopod, very similar to a Sepia, but with shorter arms : it is the genus 



Spirula, Lam. — 

 In the hinder part of the body of the Cuttle is an interior shell, which, however dissimilar to the 

 bone of the Sepia in figure, does not differ much from it in the manner of its formation. If we imagine 



* This appears now to have been disproved. — Kd. t X'lt. Part. 7.ooL n. s. iii. p. 339, &:e. — Ed. 



t LoliRopsis is now ascertained to have two arms, remarkalile for t On the anatomy of Sepiola and Loliffopsi.», consult Dr. (Jraiit'i 



llieir tjreat length and gracilily.— See Kerussar, in Wrn;. </« .V«<-Hn'S I paper in the 1st vol. of the Zno/. rr«>is.— F.D. 



