11* 



(T.I'HALOPOIU. 



rKPHALOPODA. 



ni 



on,' bat the explanation stop* short of bowing how the operation of 

 letting go' is effected. We well remember in our youth going far out 

 with an old fisherman of Dawlish to Tint his floating neU which he had 

 laid for the pilchard*. As we looked down into the clear blue water we 

 could eee that the number of fiah entangled wu great ; but to the great 

 discomfiture of the fisherman, who wai eloquent on the occasion, 

 almost every other fish wu locked in the embraces of a cuttle-fish 

 plying hi* parrot-like mandible* to come purpose. The fisherman 

 who seemed to regard these unbidden guests as an incarnation of all 

 eril, carried a capacious landing-net, but so quick was the sight 'of 

 these Cephalopoda, so ready were they in letting go and agile in 

 darting back or sideways clear of the net, that though the greedy 

 creature* held on to the last moment, the finhcrman did not secure 

 above three out of the crowds that had spoiled his haul. Upon 

 mentioning this to Mr. Owen, he informed us that the muscular 

 arrangement enabled the animal, when it was disposed to let go it* 

 hold, to push forward the piston, and thus in a moment destroy 

 the vacuum which its retraction had produced." The same author 

 (' Cyclopaedia of Anatomy and Physiology,' article 'Cephalopoda') has 

 stated that in the Calamary the base of the piston is inclosed by a 

 horny hoop, the outer and anterior margin of which is developed into 

 a series of sharp-pointed curved teeth. These con be firmly pressed 

 into the flesh of a struggling prey by the contraction of the surrounding 

 transverse fibres, and can be withdrawn by the action of the retractile 

 fibres of the piston. fTKtTinn.K.] 



Digestive Organs. The tongue, which is beset with horny points, 

 lies between the mandibles, and the (esophagus widens into a kind of 

 crop which leads to a gizzard nearly as fleshy as that of birds. To 

 the gizzard succeeds a third stomach, which is membranous and 

 somewhat spiral, wherein the liver, which is of considerable volume, 

 pours the bile. The rectum opens into the iufundibulum. 



Respiratory Organs. These are branchial, and the branchiae are 

 equal, symmetrical, and protected by the mantle under which they 

 are concealed. The infundibuluni, or funnel (entonnoir of the French), 

 U a fleshy pipe or passage in front of the neck, through which the 

 respiratory currents pass and the excrements are discharged. The 

 young, as in other classes, respire more quickly than the adult. Dr. 

 Coldstream saw an SUdone, one inch and a half in length, breathe 

 eighteen times in a minute, while another of the same species, four 

 inches in length, breathed only ten times in a minute. 



Circulating Organs. The higher organised Cephalopods present 

 the remarkable circumstance of having three separate and well- 

 organised hearts : one for the circulation of the arterial blood through 

 the body, the other two for the propulsion of the venous blood 

 through each gill or respiratory organ. Only the first of these 

 hearts, or the ' systemic,' is present in the Pearly Nautilus, which is, 

 according to Owen, the type of the lower order of the class. In 

 both divisions the venous system is characterised by the glandular 

 bodies appended to the branchial divisions of the vena cavo, or main 

 renous trunk. 



Sexual Organs. Separate and developed in distinct individuals. 

 It is not determined whether impregnation is effected before the 

 ova are excluded, during their exclusion, or afterwards. Cuvier was 

 of opinion that fecundation is effected by arrosement, as in the 

 majority of fishes. The ovary of the female is situated in the bottom 

 of the sac. Two oviducts receive the eggs from the ovary, and carry 

 them out across two large glands, which envelop them with a viscous 

 substance, and unite them together into bunches like grapes. 



Brain and Senses. The brain is included in a cartilaginous cavity 

 fa the head, and gives off on each side a nervous cord, which forms 

 in each orbit a large ganglion, whence proceed innumerable optic 

 nervous filaments. The eye is composed of numerous membranes, 

 and covered by the skin, which becomes transparent in front of the 

 organ, and sometimes forms folds which perform the office of 

 eyelids. Owen has observed that the cornea of Rouia is defended 

 by a circular fold of integument, which can be completely closed by 

 an orbicular sphincter in front of the eye a structure which is 

 probably required in this species in order to protect the cornea 

 against the spicula of ice, with which its native seas abound, 

 especially in the summer or thawing season. In the Calamary (Loligo) 

 on the other hand, there is no tegumeutary fold. The ear is nothing 

 more than a small cavity hollowed out on each side near the brain, 

 without semicircular canals or an external tube, and in this cavity is 

 suspended a membranous sac containing a limpid fluid and a small 

 compact stony substance or otolitho, a sort of ossiculutn auditos. 



Ink-Bags. The excretion from these bags is of a deep black, and 

 in i IK we species in which it occurs (for it is not common to the whole 

 family) It is produced by a gland appropriated to its secretion, and 

 reserved in a small bag till the exigencies of the animal call for 

 its effusion to cloud the surrounding water in order that it may 

 conceal itself. It has been long considered that the Indian Ink 

 imported from China is manufactured from this secretion, but Cuvier 

 observes that M. Ro'musat has found nothing in Chinese authors 

 confirmatory of thin opinion. That it makes an excellent ].it-n,.iit 

 even after having been buried for thousands of years in the earth is 

 proved by Dr. Buckland's fossil ink, which he submitted to a celebrated 

 painter, who immediately inquired from what colourman such good 

 sepia might be procured. 



The skin of the naked species is changeable, showing spots which 

 brighten and fade with a rapidity mijK-rior to the cuticular changes 

 of the chanueleon. 



Pood. Principally fishes and crustaceans ; but there is little doubt 

 that few animal matters come amiss to these mollusks, for they are 

 most voracious. 



Geographical Distribution. Very wide. Hardly any sea is without 

 some species of the family. Captain Ross discovered a n w genus 

 [Rouia, Owen), in the Arctic Ocean, which has since been found in 

 our own seas. Fabricius describes two species which frequent the 

 coasts of Greenland. ('Fauna Orocnlandica,' p. 361.) 



Utility. The flesh, especially that of the arms, is eitable, and is 

 considered very nutritions. Though neglected in tlic 1'ritish Islands, 

 it is brought to table in other countries. The arms, cut into portionx 

 and prepared for cookery, are to be frequently seen in the Neapolitan 

 market The cuttle-bone is used for erasures, and manufactured intu 

 ' pounce ' of the shops. The prepared ink is capable of being mode 

 into a pigment. That the Naked ( Yphalupods formed a favourite 

 dish with the ancients, and were considered not unworthy of the 

 most exquisite cookery, there U no doubt. (See for instance Athcn.rnx, 

 ' Deipnosoph.' lib. i. vi., vol. i., p. 14 : lib. vii. IxxxviL et cxxx., vol. iii., 

 pp. 140 et 199: lib. xiv. xviL, voL v., p. 255, Schweighiiuser's 

 edition.) 



The natural division of the class is into those Cephalopoda which 

 are naked (Cephalopoda nuda), and those which are protected by an 

 external shell (Cephalopoda tatacea). Of the former, Sepia officinal!*, 

 the Common Cuttle-Fish, may be taken as an example; and the 

 following cut will give a general idea of the form of a naked Cephalo- 

 pod, but this varies in the different genera. In Sepia officinal i> the 

 soft parts are supported by a firm calcareous bone, the well-known 

 cuttle-bone of the shops, and in all the naked Cephalopod- 

 including Ocytku.') now existing, it would appear that some rudiu,. ,it 

 at least of a bony, homy, or cartilaginous support is to be found. 

 [SEPIAD.E.] 



The Cuttle-Fish (Srpia nffitinalu). 



a, Srpia offirinalit ; the dotted line *how the place and rh.ipe of the dorsal 

 pied-, or cuttle-bone ; *, the lower Hide of an aceutralum of Octoput rttlyaru ; 

 r, of an acetabulum of Hrttonc. 



The .\nntiln* /''/. I//IM affords an example of the testaceous 

 Cephalopods, or those which are protected by a shell. [NAUTII 



Professor Owen has however shewn the necessity of dividing t hi < 

 order into two groups, which ho proposes to call l>iln-iiin-lii<itn and 

 Tetraljranchiata. 



The IHIiranrlilnta are characterised by possessing two branch hi- ; 

 and to this division all the Naked Cephalopoda belong, mn-h a?> tlic 

 species of the genera fiepia, to which the Common Cuttle I'i'li 

 hflungH, Loligo, Octopiu, Rwaia, and Ommattrtpha. 



The Tetrahranchiata possess four branching ; and to this division the 

 ffautilat [ N'AtTii.in.fc], and the bulk of the fossil a|>ccie!< of Cephalo- 

 poda known under the names of Ammonite*, Goniatitet, Crralilct, tic., 

 belong. The extinct animals of this division ore by far the moat 

 numerous. 



None of the Tetrabranchiata exist in the British seas ; there are 

 however several forms of Dibrcmchiata, of which the following 



