NO. 8 ANATOMICAL LIFE OF THE MOSQUITO — SNODGRASS 



6l 



23) the mouth (Mth) is seen to lie beneath the upper end of the clypeal 

 region {Clp) of the cranial wall. Below the mouth projects the large 

 tonguelike lobe commonly termed the hypopharynx (Hphy), which 

 has a long base sloping up to the mouth. On this basal part of the 

 hypopharynx is a depression that forms the floor of a pocketlike space 

 (Cb) in front of the mouth beneath the inner wall of the clypeus. The 

 masticated food passed back from the mandibles is stored in this 

 pocket before it is swallowed. The pocket, therefore, is named the 



13 Fr 



PrC 



Fig. 23. — Vertical section through the left side of the head of a cockroach, 

 exposing the preoral cavity. 



Cb, cibarium ; Clp, clypeus ; Fr, frons ; /;/, hypopharyngeal fulcrum ; Hphy, 

 hypopharynx ; Lb, labium ; Lm, labrum ; Mth, mouth ; Phy, pharynx ; PrC, 

 preoral cavity; SIDct, salivary duct; SIO, salivary orifice; y, oral suspensory 

 arm of hypopharynx. 



50,3b, dilator muscles of cibarium ; 6,7, frontal muscles of stomodaeum ; 13, 

 adductor of hypopharynx ; 14, abductor of hypopharynx. 



cibarium (food container). On its dorsal wall are attached strong 

 muscles (5a, 5&) from the clypeus. The hypopharynx can be pressed 

 against the inner clypeal wall by muscles (75) attached to arms (y) 

 from its base. The cibarium then becomes a closed chamber that can 

 be dilated by the clypeal muscles, and probably serves as a sucking 

 organ when the cockroach drinks liquids. In insects that habitually 

 feed on liquid food, the cibarium becomes elaborated to form a 

 permanent sucking pump. 



