A common form of star-fish.

Starfish

A common form of star-fish.

A common form of brittle star, dorsal view.

Brittle Star

A common form of brittle star, dorsal view.

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 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…

An extinct lily crinoid.

Lily Crinoid

An extinct lily crinoid.

Illustration of an xy grid/graph with grid lines shown. It is the Cartesian coordinate system. Neither axis is labeled.

Blank Coordinate Grid With Grid Lines Shown

Illustration of an xy grid/graph with grid lines shown. It is the Cartesian coordinate system. Neither…

Illustration of an xy grid/graph with grid lines shown. It is the Cartesian coordinate system with both axes labeled.

Coordinate Grid With Axes Labeled And Grid Lines Shown

Illustration of an xy grid/graph with grid lines shown. It is the Cartesian coordinate system with both…

A tool used to measure the tactile sensitivity of the skin.

Esthesiometer

A tool used to measure the tactile sensitivity of the skin.

Estheria californica is a species of Branchiopod crustaceans most closely resembling the shrimp.

Estheria

Estheria californica is a species of Branchiopod crustaceans most closely resembling the shrimp.

"Gules, an estoile argent," or a silver star on a red background. -Whitney, 1911

Estoile

"Gules, an estoile argent," or a silver star on a red background. -Whitney, 1911

The East Indian Leopard Gecko (Eublepharis hardwickii) is a lizard found in India.

Leopard Gecko

The East Indian Leopard Gecko (Eublepharis hardwickii) is a lizard found in India.

The Milkweed Tiger Moth (Euchaetes egle) is an insect in the Arctiidae family of tiger moths.

Milkweed Tiger Moth

The Milkweed Tiger Moth (Euchaetes egle) is an insect in the Arctiidae family of tiger moths.

The larva Milkweed Tiger Moth (Euchaetes egle) is also known as the Milkweed Tussock caterpillar.

Milkweed Tiger Moth Larva

The larva Milkweed Tiger Moth (Euchaetes egle) is also known as the Milkweed Tussock caterpillar.

A flowering branch of the Blue Gum Tree (Eucalyptus globulus), a tree in the Myrtaceae family of evergreen plants.

Blue Gum

A flowering branch of the Blue Gum Tree (Eucalyptus globulus), a tree in the Myrtaceae family of evergreen…

Eucharis americana is an insect in the Chalcididae family of parasitic wasps.

Chalcid Wasp

Eucharis americana is an insect in the Chalcididae family of parasitic wasps.

"A pelagic family of radioflagellate infusorians, typified by the genus Euchitonia. The animalcules are free-floating." -Whitney, 1911

Euchitonia

"A pelagic family of radioflagellate infusorians, typified by the genus Euchitonia. The animalcules…

Echlanis macrura is a species of rotifer, a microscopic planktonic animal.

Rotifer

Echlanis macrura is a species of rotifer, a microscopic planktonic animal.

Eucope diaphana is a species of marine animal in the order Anthomedusae.

Eucope

Eucope diaphana is a species of marine animal in the order Anthomedusae.

Eudendrium cochleatum is a hydrozoan marine animal in the Eudendriidae family.

Eudendrium

Eudendrium cochleatum is a hydrozoan marine animal in the Eudendriidae family.

The Southern Rockhopper Penguin (Eudyptes chrysocome) is a bird in the Spheniscidae family of penguins.

Southern Rockhopper Penguin

The Southern Rockhopper Penguin (Eudyptes chrysocome) is a bird in the Spheniscidae family of penguins.

Illustration used to show how to bisect a straight line.

Bisect A Straight Line

Illustration used to show how to bisect a straight line.

Illustration used to show how to draw a perpendicular to a straight line from a given point on the line when the point is at or near the center of the line.

Perpendicular To Straight Line Construction

Illustration used to show how to draw a perpendicular to a straight line from a given point on the line…

Illustration used to show how to draw a perpendicular to a straight line from a given point on the line when the point is near the end of the line.

Perpendicular To Straight Line Construction

Illustration used to show how to draw a perpendicular to a straight line from a given point on the line…

Illustration used to show how to draw a perpendicular to a straight line from a given point that is not on the line and which lies nearly over the center of the line.

Perpendicular To Straight Line Construction

Illustration used to show how to draw a perpendicular to a straight line from a given point that is…

Illustration used to show how to draw a perpendicular to a straight line from a given point that is not on the line and which lies nearly over one end of the line.

Perpendicular To Straight Line Construction

Illustration used to show how to draw a perpendicular to a straight line from a given point that is…

Illustration used to show how to draw a straight line parallel to a straight line through a given point.

Parallel To Straight Line Construction

Illustration used to show how to draw a straight line parallel to a straight line through a given point.

Illustration used to show how to construct a bisector of an angle when the sides intersect within the limits of the drawing.

Bisect An Angle

Illustration used to show how to construct a bisector of an angle when the sides intersect within the…

Illustration used to show how to construct a bisector of an angle when the sides no not intersect within the limits of the drawing.

Bisect An Angle

Illustration used to show how to construct a bisector of an angle when the sides no not intersect within…

Illustration used to show how to divide a given straight line into required number of equal parts.

Construction Of Dividing A Line

Illustration used to show how to divide a given straight line into required number of equal parts.

Illustration used to show how to divide a given straight line into required number of equal parts.

Construction Of Dividing A Line

Illustration used to show how to divide a given straight line into required number of equal parts.