part of embryonic head epidermis embryonic dorsal pouch Note - possible redundancy between primordium term and embryonic term. ds060616. FBbt:00005743 fly_anatomy.ontology Epidermal pouch in the embryonic head that incorporates the acron and dorsal regions of the head segments. It forms following the movement of the dorsal fold over the clypeolabrum and procephalic lobe. dorsal pouch