The body of the cuttlefish is soft and covered only with a leathery skin. Its eight arms are very long.

Cuttlefish

The body of the cuttlefish is soft and covered only with a leathery skin. Its eight arms are very long.

Octopus, a mollusk related to the squid. It has eight arms with suckers, arranged around a central soft, baggy body.

Octopus

Octopus, a mollusk related to the squid. It has eight arms with suckers, arranged around a central soft,…

Octopus, a mollusk related to the squid. It has eight arms with suckers, arranged around a central soft, baggy body.

Octopus

Octopus, a mollusk related to the squid. It has eight arms with suckers, arranged around a central soft,…

The squid is the best example of the cephalopod group. It is abundant along the Atlantic coast. Squids swim in schools and feed on young herring and mackerel.

Squid

The squid is the best example of the cephalopod group. It is abundant along the Atlantic coast. Squids…

As the name indicates, the octopus has eight arms instead of ten, as in the squids and cuttles.

Octopus

As the name indicates, the octopus has eight arms instead of ten, as in the squids and cuttles.

Chambered nautilus, showing chambers with soft body in outer chamber. It is closely related to the squids and cuttlefishes, but has the body enclosed in a flat-spiral shell.

Nautilus

Chambered nautilus, showing chambers with soft body in outer chamber. It is closely related to the squids…

The paper nautilus is closely related to the octopus. It creates its own thin shell, or egg case, in which it hides when disturbed.

Paper Nautilus

The paper nautilus is closely related to the octopus. It creates its own thin shell, or egg case, in…

The paper nautilus is closely related to the octopus. It creates its own thin shell, or egg case, in which it hides when disturbed.

Paper Nautilus

The paper nautilus is closely related to the octopus. It creates its own thin shell, or egg case, in…

Cephalopods are the most highly organized Molluscs. The head is distinct, carrying two large globular eyes, and having the mouth in its center.

Cuttlefish

Cephalopods are the most highly organized Molluscs. The head is distinct, carrying two large globular…

The paper-nautilus is closely related to the Octopus.

Paper Nautilus

The paper-nautilus is closely related to the Octopus.

The nautilus is a true mollusc. (a) mantle; (o) eye; (t) tentacles; (f) funnel.

Nautilus

The nautilus is a true mollusc. (a) mantle; (o) eye; (t) tentacles; (f) funnel.

Part of the cephalopod group. The name cephalopod is derived from two greek words which mean feet on head.

Octopus

Part of the cephalopod group. The name cephalopod is derived from two greek words which mean feet on…

A cuttle fish.

Cuttlefish

A cuttle fish.

"Cephalopoda is a class of mollusks, the highest in organization of the division of the animal kingdom. To this class belong the Nautili, Squids, Cuttle-fish, etc. The Cephalopoda receive their name from having organs of prehension and locomotion attached to the head, an arrangement toward which a gradual approach may be traced in the highest gasteropod mollusks."—(Charles Leonard-Stuart, 1911)

Cephalopoda

"Cephalopoda is a class of mollusks, the highest in organization of the division of the animal kingdom.…

"Argonauta argo (male), with hectocotylized arm attatched. (several times smaller than the female, though shown larger."-Whitney, 1902

Argonauta argo

"Argonauta argo (male), with hectocotylized arm attatched. (several times smaller than the female, though…

"Argonauta argo (female), swimming in the direction of the large arrow- the smaller showing the current from the siphon."-Whitney, 1902

Argonauta argo

"Argonauta argo (female), swimming in the direction of the large arrow- the smaller showing the current…

"The Octopus is the typical genus of the family Octopodidæ. The body is oval, warty, or cirrose, finless; arms long, unequal, suckers in two rows, mantle supported in front by the branchial septum. In the male the third right arm is hectocotylized. Found on the coasts of the temperate and tropical zones. Forty-six species are known, varying in length from one inch only to a number of feet. They are solitary animals, frequenting rocky shores, and are very active and voracious, the females oviposit on seaweeds or in empty shells. The term 'octopus' is applied in the United States to monopolies supposed to resemble the octopus in their grasping and voracious character."—(Charles Leonard-Stuart, 1911)

Octopus

"The Octopus is the typical genus of the family Octopodidæ. The body is oval, warty, or cirrose,…

A genus of fishes beloning to the cephalopod group, and also known as cuttlefishes. They have a warty, oval body, eight arms of unequal length, and consist of fourty-six known species.

Octopus

A genus of fishes beloning to the cephalopod group, and also known as cuttlefishes. They have a warty,…

A fish with eight arms.

Cuttlefish

A fish with eight arms.

"Hectocotylus of Tremoctopus violaceus." — Encyclopedia Britannica, 1893

Hectocotylus

"Hectocotylus of Tremoctopus violaceus." — Encyclopedia Britannica, 1893

"A genus of cephalapodous mollusca, pretty generally known by the name of Paper Nautilus, and in consequence of similarity in the form of the shell, often confounded with the genus Nautilus, but in fact much more nearly allied to the Poulpe (Octopus)." — Chambers' Encyclopedia, 1875

Argonaut

"A genus of cephalapodous mollusca, pretty generally known by the name of Paper Nautilus, and in consequence…

"A genus of dimiliarly known as cuttle-fishes. They have eight arms, each with two rows of suckers, which are sessile or unstalked. The prominent head is joined to the body by a distinct neck, and the body itself is short, generally more or less rounded in shape, and unprovided with side or lateral fins. They have attained a notoriety from tales circulated concerning their ferocity and the existence of gigantic members of the genus, though the largest cuttle-fishes that have been met with have belonged to other genera." — Winston's Encyclopedia, 1919

Octopus

"A genus of dimiliarly known as cuttle-fishes. They have eight arms, each with two rows of suckers,…

Male of Argonauta argo, with the hectocotylized arm still contained in its enveloping cyst.

Argonauta Argo

Male of Argonauta argo, with the hectocotylized arm still contained in its enveloping cyst.

"The Devil-fish (Octopus). A, at rest; B, swimming. a, arms, with suckers on the inner aspect; e, eye; s, siphon or funnel." -Galloway, 1915

Octopus

"The Devil-fish (Octopus). A, at rest; B, swimming. a, arms, with suckers on the inner aspect; e, eye;…

"The Paper Nautilus (Argonauta argo). e, eye; m, mouth; f, siphon; sh, shell; t, tentacles." -Galloway, 1915

Paper Nautilus

"The Paper Nautilus (Argonauta argo). e, eye; m, mouth; f, siphon; sh, shell; t, tentacles." -Galloway,…

"Liassic 'Thunder bolt' (Belemnites hastata)." -Taylor, 1904

Belemnite

"Liassic 'Thunder bolt' (Belemnites hastata)." -Taylor, 1904

"Oolitic 'Thunder-bolt' (Belemnites puzosianus)." -Taylor, 1904

Belemnites puzosianus

"Oolitic 'Thunder-bolt' (Belemnites puzosianus)." -Taylor, 1904

"Oolitic 'Thunder-bolt' (Belemnites abbreviatus)." -Taylor, 1904

Belemnites abbreviatus

"Oolitic 'Thunder-bolt' (Belemnites abbreviatus)." -Taylor, 1904

"Belemnites mucronatus." -Taylor, 1904

Belemnites mucronatus

"Belemnites mucronatus." -Taylor, 1904

"Natural flint cast of phragmocone of...Belemnites mucronatus." -Taylor, 1904

Belemnites Fossil

"Natural flint cast of phragmocone of...Belemnites mucronatus." -Taylor, 1904

"Belemnite (restored)." -Taylor, 1904

Belemnite

"Belemnite (restored)." -Taylor, 1904

The paper nautilus or argonaut, a cuttlefish.

Argonaut

The paper nautilus or argonaut, a cuttlefish.

"A very ugly-looking creature, which belongs to the <em>Octopodidae</em> family, is the Octopus."

Octopus Vulgaris (Lamarck)

"A very ugly-looking creature, which belongs to the Octopodidae family, is the Octopus."

"A very ugly-looking creature, which belongs to the <em>Octopodidae</em> family, is the Octopus."

Octopus Macropus (Risso)

"A very ugly-looking creature, which belongs to the Octopodidae family, is the Octopus."

"A very ugly-looking creature, which belongs to the <em>Octopodidae</em> family, is the Octopus."

Octopus Brevipes (d'Orbigny)

"A very ugly-looking creature, which belongs to the Octopodidae family, is the Octopus."

"A very ugly-looking creature, which belongs to the <em>Octopodidae</em> family, is the Octopus."

Octopus Horridus (d'Orbigny)

"A very ugly-looking creature, which belongs to the Octopodidae family, is the Octopus."

This creature, belonging to the <em>Octopodidae</em> family, "changes its color under any exertion, so that the animal at rest and in motion are two different beings."

Pinnoctopus Cordiiformis (Q. & G.)

This creature, belonging to the Octopodidae family, "changes its color under any exertion,…

"In one genera [of the <em>Octopodidae</em> family] the arms are completely united in their whole extent by a thin membrane."

Cirrhoteuthis Mulleri (Eschricht)

"In one genera [of the Octopodidae family] the arms are completely united in their whole extent…

The greater argonaut (Argonauta argo) is a cephalopod and a species of pelagic octopus also known as a paper nautilus.

Greater Argonaut

The greater argonaut (Argonauta argo) is a cephalopod and a species of pelagic octopus also known as…

The Common Cuttlefish (Sepia officinalis) is a mollusc in the Sepiidae family of cephalopods.

Common Cuttlefish

The Common Cuttlefish (Sepia officinalis) is a mollusc in the Sepiidae family of cephalopods.

The Atlantic Bobtail (Sepiola atlantica) is a cephalopod in the Sepiolidae family of bobtail squids.

Atlantic Bobtail

The Atlantic Bobtail (Sepiola atlantica) is a cephalopod in the Sepiolidae family of bobtail squids.

The blanket octopuses, four species of octopus in the Tremoctopus genus, are found in the waters of Australia's Northern Coast.

Blanket Octopus

The blanket octopuses, four species of octopus in the Tremoctopus genus, are found in the waters of…

An illustration of a Cirrhoteuthis Mulleri, a species of octopus.

Cirrhoteuthis Mulleri

An illustration of a Cirrhoteuthis Mulleri, a species of octopus.

Graneledone verrucosa is a species of cephalopods in the Octopodidae family of octopuses.

Octopus

Graneledone verrucosa is a species of cephalopods in the Octopodidae family of octopuses.

Goniatites are extinct ammonoids, shelled cephalopods related to squid, octopus, and belemnites, that form the order Goniatitida. The goniatites all possessed an external shell, which is divided internally into chambers. The animal lived in the largest of the external chambers, and the internal chambers would have been filled with gas, making the animal buoyant in the water.

Coiled Chambered Shell

Goniatites are extinct ammonoids, shelled cephalopods related to squid, octopus, and belemnites, that…

A cross sectional view of the Dicyemennea Eledones, a parasite, found in Eledone Moschata, or musky octopus.

Dicyemennea Eledones Worm Found in Kidney of Octopus

A cross sectional view of the Dicyemennea Eledones, a parasite, found in Eledone Moschata, or musky…