DoERixc: Lepyronia quadrangularis. 561 



The aedagiis (pi. LXI. figs. 7 and 8) is a term applied to the 

 stnioture containing the penis. It has been called by other writers 

 the penis sheatii, or merely the penis. It too arises from a genital 

 area on the ninth segment. In texture the a3dagus is quite heavily 

 chitinized and is very smooth and shiny. Basally the oedagus is 

 club-siiaped. flattened dorsoventrally, and gradually narrowing to a 

 long, slender, chitinous tube which extends cephalad to a point 

 beyond the anterior tips of the styles. Its apex is broadened into a 

 flat plate, whose laterocaudal angles bear two longer, slender, taper- 

 ing hooks, the penis hooks, which extend directly caudad. 



From the center of the broad plate there appears to arise a 

 slender, membranous tube, which also projects caudad, parallel with 

 the penis hooks. At the apex of the tube is a circular opening or 

 gonoporc. There is also another circular opening at the base of the 

 oedagus, which is probably the opening of the ejaculatory duct. 

 The flat apical part of the oedagus lies directly beneath the proctiger 

 or tenth uromere. The latter has on its lateral margins a small 

 hooklike structure (pi. LIX, fig. 2) which seems to fit down around 

 the oedagus and which may correspond to the surgonopods of 

 Crampton (1922). The oedagus is protective in function, since it 

 serves to protect the delicate penis. 



THE FEMALE GENITALIA. 



On the female the genitalia consist of three pairs of appendages, 

 which collectively are often spoken of as the ovipositor. More 

 properly speaking, however, the ovipositor is made up of only two 

 pairs of valves, the ventral and dorsal, and the lateral pair form a 

 sheath around them. The eighth sternum of the abdomen, as was 

 noted above, is divided into two distinct plates by the processes of 

 the ovipositor, while the ninth sternite is represented by two small 

 rectangular sclerites to which the lateral valves of the ovipositor are 

 attached. 



The lateral valies (pi. LX, fig. 3) have been given other names 

 in the literature, such as outer valves, posterior processes, or ovi- 

 positor sheaths. They are the outermost of the three pairs and 

 fold around the inner pairs as is shown in figure 1. They arise from 

 a genital area on the ninth segment and are attached in the adult 

 to the vestigial parts of the ninth sternite. The attachment is broad 

 and transverse to the caudal end of the sternite. Each lateral 

 valve is a broad, spoon-shaped appendage which is deeply concave 

 on its inner surface, so that half of it shows from a ventral view 

 of the genitalia (pi. LX, fig. 1) and half from a dorsal view (fig. 6). 



