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.

"Galerites albogalerus, Lam.; U. Chalk, Kent." — Encyclopedia Britannica, 1893

Fossil Echinidea

"Galerites albogalerus, Lam.; U. Chalk, Kent." — Encyclopedia Britannica, 1893

"Scutella subrotunda; Miocene, Malta." — Encyclopedia Britannica, 1893

Fossil Echinidea

"Scutella subrotunda; Miocene, Malta." — Encyclopedia Britannica, 1893

"In this family the arms appear to be merely prolongations of the disc; they are suaully five in number, and the plates from which the ambulacra are exserted are placed in deep furrows, which run along the lower surface of the arms." — Goodrich, 1859

Five-fingered jack

"In this family the arms appear to be merely prolongations of the disc; they are suaully five in number,…

A sea-urchin very similiar to the Sand Dollar, but has 5 "keyholes" through its shell.

Keyhole-Urchin

A sea-urchin very similiar to the Sand Dollar, but has 5 "keyholes" through its shell.

An ancient crinoid, sea lilies are flowerlike, with branching arms surrounding the central mouth.

Sea Lily

An ancient crinoid, sea lilies are flowerlike, with branching arms surrounding the central mouth.

An ancient crinoid, stone lilies are flowerlike, with branching arms surrounding the central mouth.

Stone Lily

An ancient crinoid, stone lilies are flowerlike, with branching arms surrounding the central mouth.

"Metacrinus interruptus." -Parker, 1900

Metacrinus Interruptus

"Metacrinus interruptus." -Parker, 1900

A sub-kingdom of animals embracing a division of the invertebrates. It includes especially those having an unsegmented bilateral body; four nervecords arranged in pairs, two visceral and two pedal, with lateral and medial abdominal ganglia.

Mollusca

A sub-kingdom of animals embracing a division of the invertebrates. It includes especially those having…

Diagram of the nervous system of a starfish. N, nerve ring.

Nervous System of the Starfish

Diagram of the nervous system of a starfish. N, nerve ring.

"Ophioglypha lacertosa. A, outline, of the natural size; B, central disc, dorsal view; C, the disc, ventral view showing the mouth and genital fissures." -Parker, 1900

O. Lacertosa

"Ophioglypha lacertosa. A, outline, of the natural size; B, central disc, dorsal view; C, the disc,…

"This figure shows a specimen of a family in which the arms are something like the tails of serpents. This species lives in she seas of the Antilles; the five arms are each provided with three to four rows of spines."

Ophiocoma Riisea (Lutken)

"This figure shows a specimen of a family in which the arms are something like the tails of serpents.…

"Ventral surface of disc of an Ophiuroid (Ophiothrix fragilis). g., Openings of genital pockets or bursae; m., mouth; v., ventral plates of arms; sp., spines of arms; tf., tube-feet--at the right side these are represented as retracted; o., the opening through which they are protruded; p., plates around mouth bearing the so-called teeth; one of these plates is perforated, and functions as the madreporite." -Thomson, 1916

Ophiuroid

"Ventral surface of disc of an Ophiuroid (Ophiothrix fragilis). g., Openings of genital pockets or bursae;…

"Pentacrinus fasciculosus. Lias Shales, Wurtemburg; a ossicle of stem; (b ditto of another species, P. basaltiformis)." -Taylor, 1904

Pentacrinus

"Pentacrinus fasciculosus. Lias Shales, Wurtemburg; a ossicle of stem; (b ditto of another species,…

"The <em>Crinoidea</em>, which belong to the family of starfishes, are mostly attached to marine rocks by a sort of root, having a long, flexible stem, which enables them to execute movements in the circle limited only by the length of this stem."

Pentacrinus Caput Medusae (Muller)

"The Crinoidea, which belong to the family of starfishes, are mostly attached to marine rocks…

"The <em>Crinoidea</em>, which belong to the family of starfishes, are mostly attached to marine rocks by a sort of root. Another division of this family, although at first fixed to some rooted stem, in their adult state they throw off the bonds and move freely, swimming through the water water or clinging to mussel or oyster banks."

Pentacrinus Europaeus (Thompson)

"The Crinoidea, which belong to the family of starfishes, are mostly attached to marine rocks…

"This may be considered as one of the greatest wonders of nature, it being a real animal, having blood, and feeding upon other marine animals, yet having the form of a plant, and living like a plant, fixed to a rock in the deep sea." &mdash; Goodrich, 1859

Medusa's head pentacrinus

"This may be considered as one of the greatest wonders of nature, it being a real animal, having blood,…

"d Pentremites, enlarge. e Showing the plates, &c., which make up the test." -Taylor, 1904

Pentremites

"d Pentremites, enlarge. e Showing the plates, &c., which make up the test." -Taylor, 1904

"Pentremites florealis, Carb. Limestone, Illinois, United States. This fossil almost makes up the bulk of the limestone." -Taylor, 1904

Pentremites florealis

"Pentremites florealis, Carb. Limestone, Illinois, United States. This fossil almost makes up the bulk…

This specimen is yellowish; its disk about four inches, its arms sixteen to eighteen. It is a very curious inhabitant of the Indian Ocean.

Periphylia Mirabilis

This specimen is yellowish; its disk about four inches, its arms sixteen to eighteen. It is a very curious…

"A common European type of the group is the species Psammechinus esculentus. In certain forms the test is perforated by slit-like apertures." &mdash; Encyclopedia Britannica, 1893

Psammechinus esculentus

"A common European type of the group is the species Psammechinus esculentus. In certain forms the test…

In the Radiata, the starfish manifests one of the simplest forms of nervous systems. it consists of a central mass, with five arms radiating from it. In the center is the mouth, and beneath it the stomach or gastric cavity, which sends branches to each limb. The nervous system consists of five similar ganglions situated in the central portion at the base of the arms. These ganglions are connected and each sends off nerve-filaments to corresponding limbs.

Diagram of a Radiata

In the Radiata, the starfish manifests one of the simplest forms of nervous systems. it consists of…

"Rotula Augusti" &mdash; Encyclopedia Britannica, 1893

Rotula Augusti

"Rotula Augusti" — Encyclopedia Britannica, 1893

Sand dollar, the name given to a flattened looking sea urchin, very common on sandy shores.

Sand dollar

Sand dollar, the name given to a flattened looking sea urchin, very common on sandy shores.

The common sand dollar or flat sea urchin. Upper surface with the spines partly removed.

Sand Dollar

The common sand dollar or flat sea urchin. Upper surface with the spines partly removed.

A sea-urchin in the shape of a circle. Has 5 star-like markings on its top-side.

Sand-Dollar

A sea-urchin in the shape of a circle. Has 5 star-like markings on its top-side.

"Among the British species are the Common Sand-Star, <em>Ophiura texturata</em>." &mdash; Goodrich, 1859

Sand-star

"Among the British species are the Common Sand-Star, Ophiura texturata." — Goodrich,…

Scotoplanes live on or just underneath the surface of the bottom of the ocean, on the abyssal plain. They look and act a bit slug-like. They feed on the mud of the sea floor, benefiting from the organic materials that settle to the ocean bottom.

Scotoplana Globosa

Scotoplanes live on or just underneath the surface of the bottom of the ocean, on the abyssal plain.…

A sea lily (Encrinites moniliformis), a prehistoric crinoid.

Sea Lily

A sea lily (Encrinites moniliformis), a prehistoric crinoid.

A sea lily or crinoidea.

Sea Lily

A sea lily or crinoidea.

The Spiny Sea Star (Echinaster sentus) is an echinoderm in the Asteroidea class of starfish.

Spiny Sea Star

The Spiny Sea Star (Echinaster sentus) is an echinoderm in the Asteroidea class of starfish.

An diagram of the anatomy of a sea urchin. Sea urchins are small, globular, spiny sea creatures, composing most of class Echinoidea. They are found in oceans all over the world. Their shell, or "test", is round and spiny, typically from 3 to 10 cm across. Common colors include black and dull shades of green, olive, brown, purple, and red. They move slowly, feeding mostly on algae. Sea otters, wolf eels, and other predators feed on urchins. Sea urchins are harvested and served as a delicacy.

Sea Urchin

An diagram of the anatomy of a sea urchin. Sea urchins are small, globular, spiny sea creatures, composing…

Sea urchins are small, globular, spiny sea creatures, composing most of class Echinoidea. They are found in oceans all over the world. Their shell, or &quot;test&quot;, is round and spiny, typically from 3 to 10 cm across. Common colors include black and dull shades of green, olive, brown, purple, and red. They move slowly, feeding mostly on algae. Sea otters, wolf eels, and other predators feed on urchins. Sea urchins are harvested and served as a delicacy.

Sea Urchin

Sea urchins are small, globular, spiny sea creatures, composing most of class Echinoidea. They are found…

An illustration of various sea urchin fossils. "1, Palaeechinus; Carboniferous; 2, A plate and radiole of Archaeolcidaris; 3, A radiole of Cidaris; Jurassic; 4, Hemicidaris; Mid. Jurassic; 5, Salenia; Cretaceous; 6, Dyaster; Jurassic; 7, Enallaster; Cretaceous; 8, Catopygus; Cretaceous." -Britannica, 1910

Sea Urchin Fossils

An illustration of various sea urchin fossils. "1, Palaeechinus; Carboniferous; 2, A plate and radiole…

"Diagram of a portion of the ovary of Sea-urchin showing the eggs arising from the epithelium (reproductive epithelium) by constriction. e, epithelium; o, ova in different stages of growth." -Galloway, 1915

Sea Urchin Ovary

"Diagram of a portion of the ovary of Sea-urchin showing the eggs arising from the epithelium (reproductive…

"Diagram of an Echinus (stripped of its spines). a, mouth; a', gullet; b, teeth; c, lips; d, alveoli; e, falces; f, f, auriculariae; g, retractor, and h, protractor, muscles of Aristotle's lantern; i, madreporic canal; k, circular ambulacral vessel; l, Polian pedicels; r, r, spines; s, tubercle; s', tubercle to which a spine is articulated; t, t, pedicellariae; u, anus; v, madreporic tubercle; x, ocular spot." -Whitney, 1911

Sea Urchin Section

"Diagram of an Echinus (stripped of its spines). a, mouth; a', gullet; b, teeth; c, lips; d, alveoli;…

"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."

Sea Urchin without Spines, Arcocladia Mamillata

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

"Sea-urchin (Echinus esculentus). Left side in natural state; right side with spines removed, showing the bare plates." -Whitney, 1911

European Edible Sea Urchin

"Sea-urchin (Echinus esculentus). Left side in natural state; right side with spines removed, showing…

Sea-stars are Echinoderms. The order Ophiuroides is closely related to starfishes. The arms of sea stars however, differ from those of starfishes in not containing any prolongations from the stomach.

Sea-star

Sea-stars are Echinoderms. The order Ophiuroides is closely related to starfishes. The arms of sea stars…

"The colors in this are variable but brilliant - red, purple, green, and white. It measures from nine to twelve inches across, and feeds ravenously on shell-fish." &mdash; Goodrich, 1859

Common European sea-star

"The colors in this are variable but brilliant - red, purple, green, and white. It measures from nine…

Sea-urchins are Echinoderms. Their shell is mainly composed of calcareous plates.

Sea-urchin

Sea-urchins are Echinoderms. Their shell is mainly composed of calcareous plates.

The shell of a sea-urchin without spines.

Sea-Urchin

The shell of a sea-urchin without spines.

The most remarkable family of the Echinida are the <em>Sea-Eggs</em> or <em>Sea-Urchins</em> - <em>Cidaridae</em>: they consist of several species, somewhat varying in form, some being nearly flat, some oval, some heart-shaped, and some like the <em>Echinus esculentus</em>, resembling an orange in shape." &mdash; Goodrich, 1859

Sea-urchin

The most remarkable family of the Echinida are the Sea-Eggs or Sea-Urchins - Cidaridae:…

"The globular crest of this animal is made up of several hundred polygonal pieces of different sizes, of every variety of outline, and so accurately fitted to each other that the lines uniting them are nearly inperceptible." &mdash; Goodrich, 1859

Sea-urchin without spines

"The globular crest of this animal is made up of several hundred polygonal pieces of different sizes,…

Under surface of a Sea Urchin showing rows of suckers among the spines.

Under side of a Sea-Urchin

Under surface of a Sea Urchin showing rows of suckers among the spines.

Ascidia Podunculata (Milne-Edwards)"The Tunicata would not probably by taken for animals at first sight. They have neither arms, nor head, nor feet; but then they have a mouth, placed at the entrance of a digestive tube. It is a single ganglion, connected with divers small threads."

Social Tunicates

Ascidia Podunculata (Milne-Edwards) "The Tunicata would not probably by taken for animals at first sight.…

"The common British species of Solaster, S. papposus, has ordinarily 13 rays." &mdash; Encyclopedia Britannica, 1893

Solaster Papposus

"The common British species of Solaster, S. papposus, has ordinarily 13 rays." — Encyclopedia…

" The most singular of all the star fishes is the splendid Astrophyton. Its center is not unlike the gorgeous appearance of a Chinese wheel, but what a curious tie of twisting and twining tentacles." -Lupton

Singular Star Fish

" The most singular of all the star fishes is the splendid Astrophyton. Its center is not unlike the…

A sea star whose arms are soft and hairy, like a feather.

Rosy Feather Sea Star

A sea star whose arms are soft and hairy, like a feather.

The under side of an arm of a star-fish.

Under side of a Star-Fish

The under side of an arm of a star-fish.

The common starfish is a five rayed star. The central body is called the disk and the arms are the rays.

Starfish

The common starfish is a five rayed star. The central body is called the disk and the arms are the rays.

The common starfish is a five rayed star. The central body is called the disk and the arms are the rays. This is the water tube system of the starfish.

Starfish

The common starfish is a five rayed star. The central body is called the disk and the arms are the rays.…

A class of marine animals, which have a star-like body composed of a central disc extended into five or more rays. They belong to the radiates, a class of animals having a central focus with raylike projections.

Starfish

A class of marine animals, which have a star-like body composed of a central disc extended into five…

This diagram represents the vertical section through an arm and an interradis of a starfish. a, anus; amp., ampulla; c.b., circular blood vessel; c.w., circular water canal; co., caelom; co.e., caelomic epithelium; d.b., dermal branchae; e, position of the eyespot; ect., ectoderm; ent, entoderm; f, ambulacral foot; g, ambulacral foot; g, ambulacral groove; h, hepatic caeca or liver; i, insestine; i.c., intestinal caeca; mes, mesoderm; mo., mouth; m.p., madreporic body; n.r., nerve ring; os., ossicles in mesoderm; r.n., radial nerve band; r.b., radial blood vessel; r.p., reproductive pore; r.w., radial water canal; s.c., stone canal; sp., spines; z, lacunar spaces in the mesoderm.

Starfish

This diagram represents the vertical section through an arm and an interradis of a starfish. a, anus;…

This diagram shows a portion of the water-vascular system of the starfish. a, ampullae; f, ambulacral feet; m, madreporic body; p, polian vesicles; r.c., ring canal, with the upper portion removed at the right of the figure; r.t., radical water tubes; s, stone canal.

Starfish

This diagram shows a portion of the water-vascular system of the starfish. a, ampullae; f, ambulacral…

"Starfish for the class Asteroidea of the phylum Echinodermata."&mdash;Finley, 1917

Starfish

"Starfish for the class Asteroidea of the phylum Echinodermata."—Finley, 1917

An echinoderm called a starfish or sea star.

Starfish

An echinoderm called a starfish or sea star.

A Radiate Echinoderm, the starfish, Paleaster Niagarensis.

Starfish

A Radiate Echinoderm, the starfish, Paleaster Niagarensis.

"Starfish. I. Ventral surface; t.f., tube-feet extended; a.g., the ambulacral groove with the tube-feet retracted; m., the mouth. II. Dorsal surface, showing the position of the madrepore (M.); the two adjacent arms form the bivium." -Thomson, 1916

Starfish

"Starfish. I. Ventral surface; t.f., tube-feet extended; a.g., the ambulacral groove with the tube-feet…

A common form of star-fish.

Starfish

A common form of star-fish.

"Diagrammatic cross-section of starfish arm. n., Radial nerve; b.v., radial blood vessel according to Ludwig, septum in pseud-haemal vessel according to others; w.v., radial water vessel; am., ampulla; t.f., tube-foot; p.c., a pyloric caecum cut across; s.p., a calcareous spine; g., a skin-gill; lac., spaces in the wall; go., ova in ovary; a.o., ambulacral ossicle." -Thomson, 1916

Starfish Arm

"Diagrammatic cross-section of starfish arm. n., Radial nerve; b.v., radial blood vessel according to…