THE MALE GENITAL ARMATi:iil<: 



181 



A general study of the anatomy and homologies of the male genital 

 armature, from a developmental point of view, together with a com- 

 parison of them with the corresponding female organs, is still 

 needed. 



Velum penis. In the locusts (Acrydiidse) the penis is concealed 

 by a convex plate, flap, or hood, free anteriorly and attached pos- 

 teriorly and on the sides to the ridge forming the upper edge of 

 n tne tenth sternite. When about to 



unite sexually, the tip of the abdo- 



FIG. 203. End of abdomen situated 

 under the anal lobes off/ydrophi/uspiceux, 

 drawn out, seen from the ventral side : 6, 

 sternal region of 6th segment ; 7, 8, 9, seg-. 

 ments telescoped, when retracted, in 6th 

 segment ; ?, membrane connecting- Oth and 

 7th segments ; G, intromittent apparatus ; 

 vl, external lobes ; vlu, inner lobes ; pn, 

 penis. 



FIG. 204. The same 

 as in Fig. 203, seen from 

 the side : 6, the free 6th 

 segment ; 7-10, the four 

 last, when at rest, re- 

 tracted and telescoped 

 within the Oth segment, 

 with the copulatory appa- 

 ratus (g) ; vl, outer, vlu, 

 inner lobe; 10s, tergite of 

 10th segment ; 10*', stern- 

 ite of the same ; an, anal 

 opening. 



Fig. 205. Terminal 

 parts of the male copula- 

 tory apparatus of Hydro- 

 philus piceux, torn apart: 

 rlii, the two inner lobes ; 

 pn, penis ; a% membrane 

 torn from under side of 

 penis ; ej, ejaculatory duct ; 

 os, its opening on the under 

 side of the penis, directly 

 under its tip. The muscles, 

 trachesp, and nerves are not 

 drawn. 



men is depressed, the hood is drawn backward, uncovering the 

 chitinous penis. 



The suranal plate. This is a triangular, often thick, solid plate 

 or area, the remnant of the tergum of the last, usually tenth, seg- 

 ment of the abdomen, the supra-anal or suranal plate, or anal oper- 

 culum (lamina supraanalis) of Haase. In most lepidopterous larvae 

 this plate is well marked ; in those of the Platypteridse it is remark- 

 ably elongated, forming an approach to a flagellum-like terrifying 



