This gallery includes 137 illustrations of several sea star and sea urchin species. Sea stars, also called starfish, are echinoderms that are in the shape of a star, with typically five arms. Sea urchins are echinoderms tha are small, spiny sea creatures shaped like a sphere or globe.

"Diagrammatic vertical section through disc and base of one of the arms of Antedon rosacea. The section is inter-radial on the left, radial on the right. t., Ciliated openings in body wall; h., sub-epithelial ambulacral nerve; l., water-vascular canal; k., tentacle; r., mouth; s., intestine; g., central plexus, with "chambered organ" at its base; f., coelom; R1.-R3., radial plates; Br., brachial plates; u., muscle; a., axial nerve-cord; d., central capsule; C.D., centro-dorsal plate; p., cirri; e., nerve branches from central capsule to cirri." -Thomson, 1916

A. Rosacea Arm

"Diagrammatic vertical section through disc and base of one of the arms of Antedon rosacea. The section…

"1. The whole animal with c, c, contractile vacuoles 2. Portion of periphery more magnified with a, four still pseudopodia and n, four nuclei or endoplasts. 3. A young actinosphærium."-Whitney, 1902

Actinosphærium

"1. The whole animal with c, c, contractile vacuoles 2. Portion of periphery more magnified with a,…

"Ambulacra of Star-fish, As seen in a longitudinal and vertical section of one of the rays; and three of them in a separate figure on a larger scale, in which they are shown in different conditions; a, a, a, tubular feet; b, b, b, internal vesicles; c, the organ which supplies the fluid with which they are filled." — Chambers' Encyclopedia, 1875

Ambulacra

"Ambulacra of Star-fish, As seen in a longitudinal and vertical section of one of the rays; and three…

"Ambulacral system of a starfish. a, ampullae; ap, Polian vesicles; c, circular canal; m, madreporite; m', madreporic canal; p, tube-feet; r, radial vessels; r', branches to ampullae." -Parker, 1900

Ambulacral System

"Ambulacral system of a starfish. a, ampullae; ap, Polian vesicles; c, circular canal; m, madreporite;…

"The anchor-shaped calcareous spicules which are attached to and protrude from the flat perforated calcareous plates in the integument of echinoderms of the genus."-Whitney, 1902

Ancora

"The anchor-shaped calcareous spicules which are attached to and protrude from the flat perforated calcareous…

"The Shetland Argus, <em>Astrophyton scutatum, usually more than a foot across, is sometimes found on the British coast." &mdash; Goodrich, 1859

Shetland argus

"The Shetland Argus, Astrophyton scutatum, usually more than a foot across, is sometimes found on

"The body of the Asterias is supported by a calcareous envelop composed of juxta-imposed pieces at once various and numerous."

Aserias Aurantiaca (Lamarck)

"The body of the Asterias is supported by a calcareous envelop composed of juxta-imposed pieces at once…

"Tergal skeleton of Asterius rubens. a, connecting pieces; b, spinebearing plates." &mdash; Encyclopedia Britannica, 1893

Asterius Rubens

"Tergal skeleton of Asterius rubens. a, connecting pieces; b, spinebearing plates." — Encyclopedia…

"Asterias rubens. a, 4-ranked pedicelis; b, end of pedicel magnified." &mdash; Encyclopedia Britannica, 1893

Asterius Rubens

"Asterias rubens. a, 4-ranked pedicelis; b, end of pedicel magnified." — Encyclopedia Britannica,…

"Antambulacral surface of Asterias rubens. a, madreporite; a', the same magnified; b, anus." &mdash; Encyclopedia Britannica, 1893

Asterius Rubens

"Antambulacral surface of Asterias rubens. a, madreporite; a', the same magnified; b, anus." —…

"The rays are sometimes very short, or altogether wanting, the body having the form of a pentagonal disk." &mdash; Encyclopedia Britannica, 1893

Astrogonium Phrygianum

"The rays are sometimes very short, or altogether wanting, the body having the form of a pentagonal…

"Section of ray of Astropecten aurantiacus. a, vertebral ossicles; b, adambulacral ossicles; c, d, marginal ossicles; e, paxillae." &mdash; Encyclopedia Britannica, 1893

Astropectenn Aurantiacus

"Section of ray of Astropecten aurantiacus. a, vertebral ossicles; b, adambulacral ossicles; c, d, marginal…

The giant basket star (astrophyton muricatum) is an early Mesozoic invertebrate, often found around British Virgin Islands. During the day, it curls up into a tight ball shape to protect itself from predators. At night, it climbs to an elevated point to feed on plankton by extending its intricately-branched feeding arms in a bowl-like shape. Then, it coils around its prey and the tiny hooks along the length of these arms will prevent its prey from escaping.

Basket Star

The giant basket star (astrophyton muricatum) is an early Mesozoic invertebrate, often found around…

A common form of brittle star, dorsal view.

Brittle Star

A common form of brittle star, dorsal view.

Among the several species of Brittle-Star found in the British seas is the Common Brittle-Star, <em>Ophicoma rosula</em>, which displays the most varied hues, arranged in beautiful patterns." &mdash; Goodrich, 1859

Common brittle-star

Among the several species of Brittle-Star found in the British seas is the Common Brittle-Star, Ophicoma

The arms of the brittlestar are more flexible than those of the starfish. They move by lateral movements of the arms, and are much quicker than the typical starfish.

Brittlestar

The arms of the brittlestar are more flexible than those of the starfish. They move by lateral movements…

"Cidaris coronata&ndash;a common Oolitic echinoderm." -Taylor, 1904

Cidaris coronata

"Cidaris coronata–a common Oolitic echinoderm." -Taylor, 1904

"Cidaris coronata&ndash;a common Oolitic echinoderm&hellip;showing the spines attached to tubercles on right hand." -Taylor, 1904

Cidaris coronata

"Cidaris coronata–a common Oolitic echinoderm…showing the spines attached to tubercles…

A family of irregular sea urchins, flattened into a discoidal or shield like shape, with a mouth central and furnished with a masticatory apparatus.

Clypeastrid

A family of irregular sea urchins, flattened into a discoidal or shield like shape, with a mouth central…

"Common Starfish (Asterias forbesi)."-Whitney, 1902.

Common Starfish

"Common Starfish (Asterias forbesi)."-Whitney, 1902.

Crinoids are Echinoderms. They are distinguished by the fact that they are fixed, during the whole or a portion of the life of the animal, to submarine objects by means of a jointed flexible stalk or column.

Crinoid

Crinoids are Echinoderms. They are distinguished by the fact that they are fixed, during the whole or…

Crinoids are Echinoderms. They are distinguished by the fact that they are fixed, during the whole or a portion of the life of the animal, to submarine objects by means of a jointed flexible stalk or column.

Crinoid

Crinoids are Echinoderms. They are distinguished by the fact that they are fixed, during the whole or…

A Radiate Echinoderm, a Crinoid, Encrinus liliiformis.

Cinoid

A Radiate Echinoderm, a Crinoid, Encrinus liliiformis.

The echinoderm, the crinoid or feather-star.

Crinoid

The echinoderm, the crinoid or feather-star.

A modern crinoid showing steam with root or hold-fast attachment, and a crown composed of the calyx and branching arms.

Crinoid

A modern crinoid showing steam with root or hold-fast attachment, and a crown composed of the calyx…

A paleozoic crinoid, Actinocrinus tricuspidatus from carboniferous limestone in Belgium.

Actinocrinus

A paleozoic crinoid, Actinocrinus tricuspidatus from carboniferous limestone in Belgium.

A paleozoic crinoid, Actinocrinus triacontadactylus found in Carboniferous limestone in Lancashire.

Actinocrinus

A paleozoic crinoid, Actinocrinus triacontadactylus found in Carboniferous limestone in Lancashire.

A paleozoic crinoid, Cupressocrinus.

Cupressocrinus

A paleozoic crinoid, Cupressocrinus.

A paleozoic crinoid, Eucalyptocrinus rosaceus found in Devonian limestone in Eifel.

Eucalyptocrinus

A paleozoic crinoid, Eucalyptocrinus rosaceus found in Devonian limestone in Eifel.

A paleozoic crinoid, Ichtyocrinus laevis found in Silurian limestone in North America.

Ichtyocrinus

A paleozoic crinoid, Ichtyocrinus laevis found in Silurian limestone in North America.

An extinct lily crinoid.

Lily Crinoid

An extinct lily crinoid.

A paleozoic crinoid, Platycrinus trigintidactylus from carboniferous limestone in Ireland.

Platycrinus

A paleozoic crinoid, Platycrinus trigintidactylus from carboniferous limestone in Ireland.

A paleozoic crinoid, Rhodocrinus crenatus.

Rhodocrinus

A paleozoic crinoid, Rhodocrinus crenatus.

An illustration of a simple five armed crinoid with a detailed view of the tegmen of five orals. Crinoids, also known as sea lilies or feather-stars, are marine animals that make up the class Crinoidea of the echinoderms (phylum Echinodermata). They live both in shallow water and in depths as great as 6,000 meters. Crinoids are characterized by a mouth on the top surface that is surrounded by feeding arms. They have a U-shaped gut, and their anus is located next to the mouth.

Simple Crinoid

An illustration of a simple five armed crinoid with a detailed view of the tegmen of five orals. Crinoids,…

A paleozoic crinoid, Taxocrinus briareus found in Devonian limestone.

Taxocrinus

A paleozoic crinoid, Taxocrinus briareus found in Devonian limestone.

Crinoids are a species of Echinoderms: "68, Apiocrinus Royssianus (a, lower part of stem); 69, portion of a mass of crinoidal limestone; 70, Pentacrinus Wyville-Thomsoni." -Dana, 1883

Crinoids

Crinoids are a species of Echinoderms: "68, Apiocrinus Royssianus (a, lower part of stem); 69, portion…

An illustration of a cryptozonate asterid.

Cryptozonate Asterid

An illustration of a cryptozonate asterid.

A genus of sea urchines

Diadema

A genus of sea urchines

The spines are removed from most of the surface of this sand dollar.

Sand Dollar

The spines are removed from most of the surface of this sand dollar.

"A class of radiate animals, the highest in organisation of the great division of the animal kingdom. They have a digestive and a vascular system; for the former, however, there is in many of them only a single orifice; a circular and radiating nervous system has been observed in manyl they are especially characterised by their well-organised skin which in many is strengthened by calcareous plates, and in some also has the additional protection of numerous long spines. a, Asterias Tesselllata (Asteriadae); b, Spatangus (Echinidae) or sea-egg." &mdash; Chambers' Encyclopedia, 1875

Echinodermata

"A class of radiate animals, the highest in organisation of the great division of the animal kingdom.…

Echinopaedia is the name for the early or larval stages of echinoderms like sea stars and sea urchins. "A, common primitive form of Echinodermata, whence B, B', a vermiform holothurid, and C, C', a pluteiform ophiurid or echinid (pluteus) larva are derived: a, mouth; b, stomach; c, intestine; d, anus; e, ciliated band." -Whitney, 1911

Echinopaedia

Echinopaedia is the name for the early or larval stages of echinoderms like sea stars and sea urchins.…

"Echinus gracilis. a, ambulacral plates; b, poriferous zone; c, interambulacral plates." &mdash; Encyclopedia Britannica, 1893

Echinus gracilis

"Echinus gracilis. a, ambulacral plates; b, poriferous zone; c, interambulacral plates." — Encyclopedia…

"A species after death, when the weapons of death have been rubbed off; that is to say, the bristles. It has been calculated that more than ten thousand pieces, each admirably arranged and united, enter into the composition of the shell of this creature."

Buccal Armature of Echinus Lividus

"A species after death, when the weapons of death have been rubbed off; that is to say, the bristles.…

The organs of mastication of the Sea Urchin. Mastication, or chewing, is the process by which food is crushed and ground by teeth.

Masticating Apparatus of Echinus Lividus

The organs of mastication of the Sea Urchin. Mastication, or chewing, is the process by which food is…

"Encope emarginata. Encope is a genus of irregular clypeastroid sea-urchins, of the family Mellitidae." -Whitney, 1911

Encope

"Encope emarginata. Encope is a genus of irregular clypeastroid sea-urchins, of the family Mellitidae."…

"Theses animals were all supported upon a long stalk, at the extremity of which they floated in the waters of the ancient seas, spreading their arms in every direction in search of the small animals whch consitituted its food." &mdash; Goodrich, 1859

Encrindae

"Theses animals were all supported upon a long stalk, at the extremity of which they floated in the…

"Encrinite: head and piece of stem. Any fossil crinoid; a stone-lily: a term especially applied to the ordinary stalked form with a cylindrical stem and well-formed arms." -Whitney, 1911

Encrinite

"Encrinite: head and piece of stem. Any fossil crinoid; a stone-lily: a term especially applied to the…

"Encrinite: Any fossil crinoid; a stone-lily: a term especially applied to the ordinary stalked form with a cylindrical stem and well-formed arms. a, a, parts of the stem; b, b, separate joints." -Whitney, 1911

Encrinite

"Encrinite: Any fossil crinoid; a stone-lily: a term especially applied to the ordinary stalked form…

"The body is flattened and covered with several cacareous plates; the lower, or entral surface, bears the mouth and anus; and the ten slender rays are often branched to such an extent as to appear very numerous." &mdash; Goodrich, 1859

Rosy feather-star

"The body is flattened and covered with several cacareous plates; the lower, or entral surface, bears…

"Palaechinus sphaericus, Scouler; Carbouiferous, Ireland." &mdash; Encyclopedia Britannica, 1893

Fossil Echinidea

"Palaechinus sphaericus, Scouler; Carbouiferous, Ireland." — Encyclopedia Britannica, 1893

"Archaeocidaris Urii, Flem (spine and intermediate plate); Carboniferous, Ireland." &mdash; Encyclopedia Britannica, 1893

Fossil Echinidea

"Archaeocidaris Urii, Flem (spine and intermediate plate); Carboniferous, Ireland." — Encyclopedia…

"Cidaris glandifera, Goldf (spine); Jura, Mount Carmel." &mdash; Encyclopedia Britannica, 1893

Fossil Echinidea

"Cidaris glandifera, Goldf (spine); Jura, Mount Carmel." — Encyclopedia Britannica, 1893

"Hemicidaris intermedia, Flem.; Corallian, Calne." &mdash; Encyclopedia Britannica, 1893

Fossil Echinidea

"Hemicidaris intermedia, Flem.; Corallian, Calne." — Encyclopedia Britannica, 1893

"Salenia petalifers, Desm., U Greensand, Wilts." &mdash; Encyclopedia Britannica, 1893

Fossil Echinidea

"Salenia petalifers, Desm., U Greensand, Wilts." — Encyclopedia Britannica, 1893

"Dysaster ringens, Ag., Inferior Oolite, Dorset." &mdash; Encyclopedia Britannica, 1893

Fossil Echinidea

"Dysaster ringens, Ag., Inferior Oolite, Dorset." — Encyclopedia Britannica, 1893

"Hemipneustes Greenovii, Forbes, U. Greensand, Blackdown" &mdash; Encyclopedia Britannica, 1893

Fossil Echinidea

"Hemipneustes Greenovii, Forbes, U. Greensand, Blackdown" — Encyclopedia Britannica, 1893

"Catopygus carinatus Goldf., U. Greensand, Wilts." &mdash; Encyclopedia Britannica, 1893

Fossil Echinidea

"Catopygus carinatus Goldf., U. Greensand, Wilts." — Encyclopedia Britannica, 1893

"Cidaris florigemma, with spine, a, and single ambulacral plate, magnified, b, (after Wright; Coral Rag." &mdash; Encyclopedia Britannica, 1893

Fossil Echinidea

"Cidaris florigemma, with spine, a, and single ambulacral plate, magnified, b, (after Wright; Coral…

"Ananchytes ovatus, Lam.; U. Chalk, Europe." &mdash; Encyclopedia Britannica, 1893

Fossil Echinidea

"Ananchytes ovatus, Lam.; U. Chalk, Europe." — Encyclopedia Britannica, 1893

"Pygaster semisulcatus, Ph.; Inf. Oolite, Cheltenham." &mdash; Encyclopedia Britannica, 1893

Fossil Echinidea

"Pygaster semisulcatus, Ph.; Inf. Oolite, Cheltenham." — Encyclopedia Britannica, 1893