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SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 139 



When we turn now to the mosquito, a section of the head (fig. 

 24 A) will show beneath the bulging clypeus (Clp) a small elongate 

 capsule (CbP), which is the primary sucking pump. The basinlike 

 lower wall is strongly sclerotized and, in the female, is directly con- 



Fig. 24. — The sucking apparatus of an adult mosquito. 



A, Diagrammatic section of female head. B, Culex sp., section of pharyngeal 

 pump (from Thompson, 1905). C, Aedes aegypti, pharyngeal pump exposed 

 by removal of anterior head wall. D, Same, muscles of labrum. E, Same, 

 cibarial and pharyngeal pumps, left, cibarial pump opened to show lumen and 

 dilator muscles. 



at, anterior tentorial pit ; Br, brain ; CbP, cibarial pump ; For, occipital 

 foramen ; FrG, frontal ganglion ; Ivr, labral lever ; MxPlp, maxillary palpus ; 

 Oe, oesophagus ; PhP, pharyngeal pump ; sc, salivary canal ; SIP, salivary pump ; 

 SoeG, suboesophageal ganglion ; Tnt, tentorial arm ; y, oral arm of cibarial pump. 

 Other lettering as on figure 23. 



tinuous with the supper surface of the hypopharynx (HpJiy). The 

 dorsal wall (E) is the so-called epipharyngeal surface from the 

 labrum (Lm) to the mouth (Mth), and is thin and flexible. On it is 

 attached a great mass of dilator muscles (5) from the clypeus. The 



