Dr. Karl Krapelin on the Pulicidge. 53 



by a dorsal and two lateral channels (labrum and mandibles) . 

 its anterior section only more or less enclosed laterally by the 

 multiarticulate terminal palpi of the labium, and at the base, 

 besides the latter, by the lamelliform palpigerous raaxillge. 

 Salivary efferent ducts paired, developed as a channel along 

 the inner surface of the mandibles. No "sucking-stomach." 

 Thoracic segments free, without wings and halteres, with 

 pleural processes upon the last two segments. 



3. Rhynchota. Insects usually with imperfect metamor- 

 phosis. Head free or broadly united to the thorax, with or 

 without facetted eyes. Buccal organs usually suctorial. 

 Sucking-tube (in the higher groups) composed off two lateral 

 half-channels (the mandibles), only in the anterior portion 

 enclosed by the labium and its apical multiarticulate palpi, 

 which are united nearly to the apex ; at the base by the 

 labrum. Maxilla styliform, without palpi, applied laterallv 

 to the mandibles in the channel of the labium or the labrum. 

 Salivary efferent duct unpaired, formed by two half-channels 

 of the mandibles closing too-^^ther from the sides. No 

 " sucking-stomach." Thoracic segments free or amalga- 

 mated. Four, two, or no wings ; no halteres. 



EXPLANATION OF PLATE UI. 



The letters in all the figures refer to the same parts: — Ir, labrum; 

 m d, mandibles ; m, maxillae ; m t, maxillary palpi ; /, labium ; I p, labial 

 palpi ; /*, hypopharynx ; n, food-canal ; s, salivary duct. 



Fiy. 1. Transverse section through the proboscis of Tabanus, sp., anterior 

 third. 



Fiff. 2. Transverse section through the proboscis of Melophaffus ooinus, 

 middle. 



Fiy. 3. Transverse section through the proboscis of Culex pipiens $> 

 middle. 



Fi(j. 4. Maxilla of Sarcopsylla penetrans, side view. 



Fiy. 5. Labium of Cicada, sp., side view. 



Fig. 6. Lower part of the maxilla of Cicada sp., and its union with a 

 lamelliform appendage {pi) of the fore part of the head. /', 

 whip-like process of the plate ; p m, protrusor ; /■ m, retractor of 

 the maxilla ; sp and s r, the sinews belonging to them. At .v the 

 sinew of the protrusor articulates with a chitinous rod which is 

 perpendicular to the surface of the plate, and therefore does not 

 appear distinctly in the figure. 



Fiy. 7. Maxilla of Pidex irritans. 



Fiy. 8. Labium of Sarcopsylla j^enetrans from above. 



Fiy. 9. Tjabium of Ptdex irritans, side view, ch, basal chitinous piece. 



Fiy. 10. Transverse section through the proboscis of Ptdex irritans, an- 

 terior third. 



Fiy. 11. Transverse section through the rostrum of Notonecta ylauca, 

 basal third. 



