dorsal organ
From ZooTerms (Dictionary of Invertebrate Zoology)
dorsal organ: 1. (Annelida: Polychaeta) In Orbiniida and Spionida, ciliated sensory tubercles, ridges, or bands located on the dorsal surface of the segments. See also lateral organs.
2. (Arthropoda: Crustacea) Thickened glandular area of hypoderm on the dorsal surface in the posterior or anterior part of the cephalon.
3. (Arthropoda: Insecta) A distinct mass of cells in the dorsal part of an embryo.
