Ecdysozoa

Abdomen

the posterior part of the body

Antennae

a sensory appendage on the head of animals

Antennule

the first pair of antennae

Biramous

double branched appendages

Book Gills

primitive gills of horseshoe crabs located on the lower abdomen

Carapace

a hard shell that functions as a protective or defensive covering

Cephalothorax

a fused head and thorax; body region in athropods

Chelicerae

one of a pair of claw-like feeding appendages characteristic of chelicerates

Chelipeds

a pair of legs that possesses a pincer like chela

Compound eyes

a type of a eye composed of repeating units of cornea, lenses, and photoreceptor cells

Digestive gland

a structure that secretes digestive enzymes

Ecdysis

the shedding or molting of skin

Gastric mill

a series of plates or ossicles that are moved by muscles and function as a grinding apparatus

Green gland

a excretory organ found in some crustaceans, located in the head region

Mandible

jaw like appendage

Maxilipeds

appendages modified for feeding that are located behind the maxillae

Nerve cord

a group of nerve fivers that connects segmental nerve ganglia

Palp

an appendage that functions as a sensory organ (touch and taste)

Prothorax

the anterior segment of the thorax

Rostrum

a beaklike appendage; a piercing mouthpart

Spiracles

openings that lead to the tracheal respiratory system; located on the abdomen of some insects

Swimmerets

elongated appendages in crustaceans located on the lower abdomen; used in sexual reproduction

Telson

the last segment of the abdomen

Uniramous

single branched appendages