calyx
From ZooTerms (Dictionary of Invertebrate Zoology)
area into which structures are set.
calyx (noun; plural calyxes, calycis, calyces; Greek kalyx, cup): 1. Any cuplike
2. (Arthropoda: Insecta) a. A flattened cap of neuropile in an insect brain, a component of the corpus pedunculatum. b. In certain female insects, an expansion of the oviduct into which the ovarioles open. c. In male Lepidoptera, a funnel-shaped expansion of the basal part of the vas deferens.
3. (Cnidaria: Anthozoa) The spicules containing the basal portion of the anthocodium of some soft corals; calice.
4. (Echinodermata: Crinoidea) The body disk that is covered with a leathery tegumen containing calcareous plates.