corpus
From ZooTerms (Dictionary of Invertebrate Zoology)
structure.
corpus (noun; plural corpora; Latin corpus, body): 1. A body or
2. (Arthropoda: Insecta) a. The body. b. In many Collembola, the basal part of the minute pair of appendages on the 3rd abdominal segment; the appendages themselves known as the retinaculum or hamula.
3. (NEMATA) The most anterior part of the esophagus, usually cylindrical in shape, but may be subdivided into a slender anterior portion (procorpus) followed by a swollen, often valved, bulb (metacorpus).