The antennae are richly covered with sensory organs known as sensillae.

In males, the fourth left or right arm develops into a secondary sexual organ known as the hectocotylus.

Instead, when threatened by a bird or other predator, they produce a forked, orange-coloured organ known as an osmeterium.

The head contains a pair of sensory organs known as the Tömösváry organs.

Male rattlesnakes have sexual organs known as hemipenes, located in the base of the tail.

Rosenmüller's organ: Also known as the parovarium.

The left arm of pair IV in males is modified into a sexual organ known as the hectocotylus.

The principal organs of government at these levels, known as national committees, functioned in accordance with the principle of the so-called democratic centralism.

Vertebrates have a special organ, known as the pineal, to detect the daily changes in light.

The orders were abolished by Peter the Great and replaced, beginning in 1717, with administrative organs known as collegiate.