part of larval ocular segment embryonic/larval dorsal pouch FBbt:00001857 Note - possible redundancy between primordium term and embryonic term. ds060616. larval dorsal pouch Pouch shaped epidermal structure in the embryonic and larval head formed by the movement of the dorsal fold. The embryonic dorsal pouch incorporates the acron and dorsal regions of the head segment. In the larva, it branches dorsally from the larval atrium, just behind the mouth. It contains the dorsal section of the cephalopharyngeal skeleton (dorsal bridge and dorsal arms). fly_anatomy.ontology embryonic/larval foregut dorsal pouch