mesomere
From ZooTerms (Dictionary of Invertebrate Zoology)
mesomere (noun; Greek mesos, middle; meros, part): 1. A blastomere of medium size.
2. A mesoblastic somite.
3. Central zone of coelomic pouches in an embryo.
4. (Arthropoda: Insecta) The inner divisions of the phallic lobes that unite to form the aedeagus (the intromittent organ).
