(noun; Latin collare
, band for the neck): 1. Any of various structures comparable with a collar.
2. (Annelida: Polychaeta) Specially developed outgrowths carried on the first thoracic segment of certain worms that function in tube-building in association with calcium-secreting glands.
3. (Arthropoda: Chelicerata) In Acari, a circular line or ridge at the place of epiostracal attachment of setae, ungues, and rutellum.
4. (Arthropoda: Insecta) Between the head and thorax. a. The neck in Hymenoptera. b. In Diptera, the neck; the prothorax; sclerites attached to the prothorax or its processes. c. In Coleoptera, the prothorax. d. In Lepidoptera, the sclerites attached to the prothorax, shielding the neck. e. In Heteroptera, the anterior constricted part of the pronotum, usually set off by a groove.
5. (Bryozoa: Gymnolaemata) In Ctenostomata zooids, a pleated membranous structure attached to the diaphragm.
6. (Cnidaria: Anthozoa) The scapus of sea anemones, standing up as a prominent fold, before joining the capitulum; the parapet.
7. (Porifera) Monaxons that project obliquely upwards from the pinacoderm.