Plate LX 



the hog louse, haematopinus suis linne 



1, Transverse section through anterior region of head just posterior to section shown in Plate LXI, 1 

 fa, buccal plate; b, dorsal element of piercers; e, anterior ends of pumping pharyngeal tube; 1, structures 

 corresponding to " mandibles " of Sikora; mm, muscles of these; nn, dorsal protractors of buccal plate; 

 o, prefrontal ganglion); 2, dorsal aspect of anterior part of stomodaeum (a, buccal plate; e, pumping 

 pharyngeal tube; g, pumping pharynx; k, pharynx; nn, dorsal protractor muscles; pp, ventral protractot 

 muscles; qq, anterior dorsal retractor muscles; rr, posterior dorsal retractor muscles; ss, dorsal muscles of 

 pharynx; t, esophagus; uu, " mandibles " of Enderlein; w, lateral tendon muscles; w, haustellum with 

 buccal teeth; dilator muscles of pumping pharynx not shown) ; 3, ventral aspect of anterior part of 

 stomodaeum fxx, ventral retracjtor muscles; other lettering as in 2"); 4, ventral aspect of haustellum pro- 

 truded and showing buccal teeth; 5, transverse section through anterior region of thor:ix, showing posterior 

 ends of rami of piercers with their muscle attachments (a, cuticula enclosing piercers and esophagus; b, 

 dorsal element of piercers; d, ventral element of piercers; ee, occipital apodeme; i, aorta; k, recurrent 

 nerve; 11, tracheae; m, connectives; nn, posterior arms of apodemes of prothorax and presternum; o, salivary 

 gland between rami of piercers; t, esophagus); 6, mouth parts (b, dorsal element of piercers; c, salivary 

 duct; dd, rami of ventral element of piercers; o, salivary gland between rami of piercers; p, anterior end of 

 chitinous plate imbedded in floor of sheath; ee, protractor muscles of sheath and piercers; 11, ventral lateral 

 retractors of sheath and piercers; mm, dorsal lateral retractors of sheath and piercers; nn, posterior 

 retractors of sheath and piercers; posterior retractors inserted in end of each ramus not shown; sheath torn 

 away leaving only ventral plate and piercers, so that lateral retractor muscles appear in approximate 

 position); 7, dorsal element of piercers (a, bulb at end of salivary duct; salivary duct underlying piercer 

 shown as a dotted line in proximal part only); 8, ventral element of piercers (p, chitinous plate imbedded 

 in floor of sheath); 9, anterior ends of ventral elements of piercers 



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