Plate LXI 

 the hog louse, haematopinus suis linne 



1, Transverse section through stomodaeum at anterior level of attachment of basal partof "mandibles'* 

 of Enderlein to lateral wall of head (a, buccal plate; b, dorsal element of piercers; c, salivary duct; d, ventral 

 element of piercers) ; 2, transverse section through stomodaeum at anterior level of " mandibles " (e, pump- 

 ing pharyngeal tube; other lettering as in 1); 3, transverse section through stomodaeum at posterior level 

 of " mandibles " (lettering as in 1 and 2); 4, transverse section through stomodaeum in posterior region of 

 buccal plate (aa, posterior arms of buccal plate; f, ridge on dorsum of pumping pharj'nx; other lettering 

 as in 1 and 2); 5, transverse section through stomodaeum in region of anterior dorsal chitinous plate (g, 

 pumping pharynx; h, piercer sheath; other lettering as in 1); 6, transverse section through stomodaeum 

 immediately behind anterior chitinoua plate (ii, tendons of dorsal retractors of buccal plate; other lettering 

 as in 5); 7, transverse section through stomodaeum just after its separation from piercer sheath (lettering 

 as in 6) ; 8, transverse section through anterior region of pharynx (k, pharynx) ; 9, transverse section through 

 posterior region of pharynx behind first dorsal chitinous plate (jj, hollow tendons of central elevator muscles; 

 k, pharynx) 



(All drawings on this plate made with oil immersion and drawn to scale) 



732 



