Abdomen – body region posterior to carapace; the “tail”

Antenna – second and more lateral of the two paired appendages on anterior end of body

Antennal scale – lateral rigid lamellar outgrowth of antenna

Antennule – first, or inner, paired appendage projecting from anterior end of body

Anterior – of, pertaining to, or toward the front; “head end”; opposite of posterior

Anterolateral – front side of a structure

Article – any one of the divisions of a segmented appendage

Biramous – two-branched, as opposed to uniramous or single-branch

Carapace – “head shield”, hard protective covering anterior to abdomen

Cephalothorax – fused part of body anterior to abdomen

Chela – “hand”, claw or pincer of first pereiopod, consisting of the two distal segments, in which a movable finger opposes a fixed finger formed by a distal extension of the next to last segment.

Cheliped – whole appendage bearing chela or pincer

Distal – situated away from point of origin or attachment; in limbs, furthest from body; opposite of proximal

Dorsal – pertaining to the back; opposite of ventral

Dorsolateral – upper side of a structure

Endopod – inner branch of a two-branched appendage

Epipod – process arising from basal joint of limb, which may extend into gill chamber

Exopod – outer branch of a two-branched appendage

Flagellum – the distal multiarticulate whip-like portion of antennules or antennae

Longitudinal – running lengthwise

Lateral – pertaining to the side; located away from the midline

Maxilliped – one of three paired mouthparts anterior to pereiopods; most prominent third (outer) maxilliped resembles pereiopods

Middorsal – upper middle of a structure

Orbit – the region of the carapace nearest to the eyes

Peduncle – the combined basal segments of antennules and antennae proximal to the flagellum

Pereiopod – one of the five walking limbs, with or without chela

Pleopod – one of the paired swimming limbs on first five abdominal segments

Posterior – of, or pertaining to, the rear end; opposite of anterior

Proximal – towards or near to the point of origin or attachment opposite of distal

Rostrum – the “head spine”, or anterior projection between eyes

Seta(e) – bristle-like flexible outgrowth of body or appendage

Shield – frontal calcified portion of carapace in hermit crabs, excluding softer posterior portion.

Spine – sharp and stiff outgrowth of body or appendage

Sternum – totally or partially fused ventral plates of body segments

Subchela – imperfectly chelate; pincer in the family Crangonidae where terminal segment folds back against next to last segment

Transverse – placed crosswise; running from side to side

Tail fan – consisting of two pairs of uropods and telson

Telson – terminal segment of abdomen

Uniramous – single branch, as compared to biramous or two-branched

Uropod – one of paired appendages on last abdominal segment

Ventral – pertaining to the underside, the side opposite the back (dorsal)