348 W. D. FUNKHOUSER 



of its biological use. It is from this tube that tiie honeydew is ejected 

 which is so eagerly sought by ants. There can be little doubt that this 

 substance is entirely excretory in nature and probably represents nothing 

 more than the usual intestinal waste product. Its elimination, however, 

 in those species attended by ants, is a process of some interest. When 

 approached by an ant, the membracid nymph elevates the ninth abdominal 

 segment to almost a right angle with the body. The ant then strokes 

 this segment with its antennae and forelegs, upon which the membracid 

 protrudes the anal tube and exudes from this segment a drop of clear 

 liquid which is at once taken by the ant. Not all species are attended by 

 ants, but the anal structure seems to be about the same thruout the family. 

 In some cases the adult as well as the nymph gives off this secretion. 

 Careful histological stvidy fails to reveal the presence of glands in the anal 

 region, and there seems to be no physiological provision for any special 

 secretions which might differentiate the waste of one species from that of 

 another; so that the particular element which causes certain species to be 

 sought after by ants, and others to be ignored, is not known. 



The apical segment of the abdomen of the adult can be discussed only in 

 relation to the different sexes, since the modifications in the sclerites 

 caused by the development of genital organs are quite distinct in the 

 male and the female. 



The female 



The genital structure in the female is shown in Plate xxxvii, 6, 8. 

 The sterna of segments ii to v, inclusive, are comparatively uniform, each 

 being a broad, flat, slightly curved plate extending across the abdomen. 

 The sixth sternum is indented at its median posterior margin, and the 

 entire ventral part of the segment is usually much recurved. The sternum 

 of the seventh segment is deeply notched in its median part to inclose the 

 rounded base of the ovipositor. This is the last entire segment in the 

 female abdomen and its shape vari(>s greatly according to the type of 

 ovipositor surrounded (Plate xxxviii, 1-10). The structure of this 

 sternum has been used successfully as a specific character in the genus 

 Stictocephala (Van Duzee, 1908 a -.42) and will doubtless be found valuable 

 in other genera. In some cases the sternum is so deeply indented that 

 from an external view it appears as two separate sclerites. The eighth 

 segment may or may not show a sternum, but if one is present it is reduced 



