part of develops from clypeo-labral disc adult pharynx adult cibarium cibarial pump adult atrium Jurgens et al. (1986) define the larval cibarium as being the same as the pharynx, and posterior to the atrium. Here it only refers to the portion proximal to the hypopharynx (same as the larval atrium), following Campos-Ortega and Hartenstein (1985). FBbt:00004526 The proximal portion of the adult pharynx, which functions as a sucking pump. It consists of two arched sclerotized plates. The posterior plate is fixed in position by its connections with the clypeus. The anterior plate fits against the concave side of the posterior plate and bears a ridge shaped apodeme (apodemal carina) that is attached to large dilator muscles that attach to clypeus. Their contraction pulls the anterior plate forward, enlarging the cibarial lumen and thus producing suction. fly_anatomy.ontology rostrum anterior ectoderm derivative ventral ectoderm derivative gut section