Doerixg: Lepyroma qiadrangularis. 559 



with ils caudal margin sonirwhat cuvving. The eighth pk'ura and 

 tergum appear quite nonual. 



Tlu^ ninth segment, or pinjojir, is greatly enlarged and intlaled, 

 even more so than in the male. The anal tube is borne on its dorsal 

 surface, but occupies a more caudal position than in the male. For 

 this reason the pygofer is more bulblike, extending around on the 

 ventral surface, and thus making up a large share of the posterior 

 end of the female abdomen. Its median margins do not meet on the 

 ventral surface, since the valves of the ovipositor extend between 

 them. There appears to be no ninth pleuron externally, as its 

 position is occupied by the tergum, but a remnant of the nintb 

 sternum (pi. LIX, fig. 6) is to be seen, forming the two slender basal 

 parts of the dorsal valves of the ovipositor. 



The anal tube, as in the male, consists of the tenth and eleventh 

 segments plus the triangular telson, and is attached to the posterior 

 region of the pygofer by a membrane which fits into a circular 

 opening. The eleventh segment is greatly reduced, however, being 

 about one-eighth as long as the same segment of the male. 



THE MALE GENITALIA. 



From an external view of the abdomen part of the so-called 

 "iHternal genitalia," as well as the "external genitalia," are visible. 

 The organs usually included as "internal genitalia" are the paired 

 styles, the cedagus and the connective. The parts wdiich are exposed 

 are the apical two-thirds of the styles. These are plainly visible on 

 the dorsal surface of the abdomen and have no protective covering 

 of any sort. 



The basal parts of the styles, the connective, and the oedagus are 

 situated in a genital or terminal chamber formed by the pygofer 

 and anal tube. Since this chamber is really not closed, but is open 

 beneath the anal tube, these parts are not really internal, but are 

 only designated as such for convenience. 



There is no indication of the presence of the diaphragm, which 

 Gifford (1922) found to be present in the genital chamber of the 

 Delphacidse. In fact, the entire genital chamber of these insects 

 varies considerably from that of Lepyronia. 



The genital plates (pi. LIX, fig. 1) are two valvelike processes 

 on the ventral surface of the abdomen. They have been given vari- 

 ous names, such as hypovalvae, ventral plates, and genital plates. 

 They are large, prominent flat plates, occupying most of the apical 

 end of the abdomen, and arc broad at the base but taper to a pointed 



