Mouth-parts in Plectrofarsus and iEtlialoptera. 29 



{:]) Tlie hypophari/n.v, a lon<z narrow plate, covering tlie 

 sfa k or peduncle of the haustelliim. 



(4) The >V.s< ma.vilht. The sides of the el<)n:,'ate peduncle 

 ot" tlie hanstellnni are held in by the cardo and stipes of the 

 first maxilla. The cardo is very long and articulates with 

 the base of the skull in a small niche or angle. The stipes is 



Fiyr. 6. 



a. yiiAiih-Y^'rii oi riedrotarius gravenhorstii, to show internal structure 



of the haustellum. Side view, diagrammatic. 



b. Basal haustellar sclerite, seen from behind. 



C, cardo; St, stipes; Hyp, hypopharynx ; MP, maxillary palpus; 

 H, haustellum ; LP, labial palpus ; S.P., semicircular piece ; 

 £.H Sc, basal haustellar sclerite. 



shorter and carries the 5-segmented palpus (In the c? 3-seg- 

 mented) and the maxillary lobe. Tiie third and fourth 

 .segments of the palpus in the ? each show at their distal 

 ends a circular imprtss'on, probably sensory areas, as they 

 are known to occur on the antennae of other insects. The 

 lobes aie carried in an abnormal position. In shape long 



