140 



pharynx. The labrum is blended with the epipharynx, 

 but does not extend to the tip. 



The hypo-pharynx. Is a thin, flat two-edged lamella 

 closely applied to the under surface of the epipharynx. 

 It is pierced by the salivary duct down which the 

 salivary secretion and sporozoits pass. The opening 

 of the duct is continued as a groove reaching almost 

 to the tip of the hypopharynx. 



Fig. 52. Showing relation of Pharyngeal and Salivary Pumps to the 



Proboscis 



The mandibles. Are very fine chitinous rods, in 

 cross section crescentic in shape. At the tip of the 

 mandibles are about thirty serrations, though in certain 

 species of Culex these appear to be absent. 



The mandibles are closely applied to the sides of 

 the epipharynx. 



The maxillae. Are stouter than the mandibles, 

 and fit around the outer side of these and the hypo- 

 pharynx. They have about twelve serrations at the 

 extremity, coarser than those of the mandibles. In 

 some Culices, papillae replace the serrations. 



The Maxillary Palps. These lie upon either side 

 and somewhat dorsally to the proboscis. In the act 



