This glossary describes the terms used in formal descriptions of spiders; where applicable these terms are used in describing other arachnids.
Links within the glossary are shown .
Terms
A
Abdomen or opisthosoma: One of the two main body parts (tagmata), located towards the posterior end; see also Abdomen § Other animals
Accessory claw: Modified at the tip of the in web-building spiders; used with to grip strands of the web
Anal tubercle: A small protuberance (tubercule) above the through which the anus opens
Apodeme: see
Apophysis (plural apophyses): An outgrowth or process changing the general shape of a body part, particularly the appendages; often used in describing the male : see
Atrium (plural atria): An internal chamber at the entrance to the in female haplogyne spiders
B
Bidentate: Having two
Book lungs: Respiratory organs on the ventral side (underside) of the , in front of the , opening through narrow slits; see also Book lungs
Branchial operculum: see
Bulbus: see
C
Calamistrum (plural calamistra): Modified setae (bristles) on the of the fourth leg of spiders with a , arranged in one or more rows or in an oval shape, used to comb silk produced by the cribellum; see also Calamistrum
Caput (plural capita): see
Carapace: A hardened plate (sclerite) covering the upper (dorsal) portion of the ; see also Carapace
Carpoblem: The principal on the male ; also just called the tibial apophysis
Cephalic region or caput: The front part of the , separated from the thoracic region by the
Cephalothorax or prosoma: One of the two main body parts (tagmata), located towards the anterior end, composed of the head ( or caput) and the thorax (thoracic region), the two regions being separated by the ; covered by the and bearing the , legs, and mouthparts
Cervical groove: A shallow U-shaped groove, separating the and thoracic regions of the
Chelate: A description of a where the closes against a tooth-like process
Chelicera (plural chelicerae): One of two appendages at the front of the , made up of basal portion, the , and the ; sometimes called the jaw; see also Chelicerae
Cheliceral furrow: A shallow groove on the basal portion of a accommodating the , usually having on its margins
Cheliceral tooth: A tooth-like extension on the margin of the
Chilum: A small hardened plate (sclerite) at the base of the , under the
Claw: see
Claw tuft: A dense group of hairs or bristles (setae) underneath the paired , usually well developed in hunting spiders
Clypeus: The area of the between the anterior (frontmost) and the anterior edge of the carapace
Colulus: A short protuberance in the middle of the underside of the in front of the , considered to be a modification of the
Conductor: see
Copulatory duct: An internal tube (duct) from the through which sperm enters the female; separate from the duct through which fertilized eggs pass in entelegyne spiders
Copulatory opening: An opening in the ventral of female spiders; in entelegyne spiders, a double opening in the through which the is inserted; in haplogyne spiders, a single opening through which male is inserted
Coxa: see
Crenulate: Having longitudinal ridges
Cribellum: A sieve-like plate in front of the , used in conjunction with the ; spiders with a cribellum are called cribellate, those without ecribellate; see also Cribellum
Cuspule: A small spiny outgrowth ("wart") on the and of Mygalomorphae
Cymbium (plural cymbia): The end part of the of the in a mature male, usually hollowed out and bearing the
D
Dionychous: With two on the of each leg; a feature of spiders in the clade Dionycha
Dorsal groove: see
Dorsum: The upper (dorsal) portion or surface of the body or ; the adjective dorsal may be applied to the upper portion or surface of any part of the body; see
E
Ecribellate: see
Embolus: see
Endite: see
Endosternite: An internal hardened plate (sclerite)
Entelegyne: A spider whose female has an and separate ducts leading to for sperm storage and to the uterus for fertilization, creating a "flow-through" system; see ; see also Entelegynae
Epigastric furrow or epigastric fold: A transverse slit towards the front (anterior) of underside of the ; the front pair of open at the edge of this furrow as do the genital openings ()
Epigyne or epigynum (plural epigynes): A hardened plate on the underside of the female in which the are located; only fully developed in mature females of spiders; see also Epigyne