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- EXPLANATION OF PLATE VII. 
Fig. 1. Slightly schematised reconstruction of the right half of the head of 
Pediculus hwmanus, viewed in the sagittal plane. 
Fig. 2. The piercing apparatus. 
EXPLANATION OF LETTERING FOR TEXT-FIGURES 
AND PLATE. 
as. anterior pharyngeal sphincter ; bc. buccal cavity ; bp. buccal plate; bt. 
buccal teeth; 6.tub. buccal tube; br. brain; dv. piercer diverticulum ; 
dp. dorsal piercer ; dpp. dilatators of pumping-pharynx; f6. fat-body ; 
jr.g. frontal ganglion; da. ?labium ; lcbp. left cornu of buccal plate ; 
dp. left dorsal protractor of buccal cavity ; lvd. left ventral dilatator of 
pharynx; lvp. left ventral protractor of buccal cavity; md. mandible; 
mdi. musculus digastricus; mo. mouth ; oes. oesophagus ; p.gl. Paw- 
lowsky’s gland ; pi. pharynx ; p.ph. pumping-pharynx ; ps. pharyngeal 
strainer ; p.sh. piercer-sheath ; p.sp. posterior pharyngeal sphincter ; 
rebp. right cornu of buccal plate ; rdd. right dorsal dilatator of pharynx ; 
rdp. right dorsal protractor of buccal cavity ; rp. retractors of piercers ; 
rpdd. right posterior dorsal dilatator of pharynx ; rrbc. right retractor of 
buccal cavity ; rvd. right ventral dilatator of pharynx ; rvp. right ventral 
protractor of buccal cavity ; sd. ?salivary duct ; s.oe.g. sub-oesophageal 
ganglion ; vp. ventral piercer. 
