1922] Walker: Structure of Orthopteroid Insects 73 



23. Same, posterior view of penis with parameres everted. The spermatophore 



sac is obliterated and the genital aperture concealed by the ventral lobe. 



24. Same, lateral view "of penis with parameres almost completely everted. 



Potash preparation. 



25. Same, dorsal view of penis, with parameres retracted and inner parts 



exposed. Potash preparation. The parameres are tinnaturally retracted 

 owing to removal of enveloping muscles. 



26. Ceuthophilus aridiis Bruner? Posterior view of end of abdomen with penis 



very strongly retracted. The roof of the penis is drawn below the level 

 of the ventral lobe, the walls thus forming a pair of lateral ridges. The 

 pseudosternite is forcibly elevated to show the small arched passage (ar ej) , 

 which bridges over the ejaculatory duct in the retracted condition. 



27. Ceuthophilus macidatus (Harr.). Posterior view of end of abdomen, the 



penis everted, but the parameres probably only partly so. 



28. Ceuthophilus lapidicola (Burm.). Late nymphal stage. Dorsal view of penis 



with internal parts exposed. Potash preparation. 



Plate IV. 

 (Orthoptera — Tettigonoidea) . 

 29 Neduba carinataW alk. Posterior view of end of abdomen, vs,* the valve-like 

 plates on the under side of the fold (fps) that separates the spermatophore 

 sac proper from the paramere sac. 



30. Same, dorsal view of separated penis; potash preparation. The pseudosternite 



(pst) is represented only by a membranous fold (cut away on the right 

 side), pmo, opening into paramere, occupied by muscles in the natural 

 condition. 



31. Same, lateral view of separated penis; potash preparation. 



32. Conocephalus brevipemiis (Scudd.). Posterior view of penis. 



33. Same, dorsal view of penis. 



34. Conocephalus fasciatus (DeGeer). Last stage of nymph; posterior view of 



end of abdomen. The parameres are represented only by a slight chitmi- 

 zation of the roof of the penis, just inside the wide genital aperture. 



35. Cyphoderris monstrosa Uhl. Posterior view of end of abdomen, cps, a large, 



hook-like copulatory process, arising from the vertically placed sternum 

 of segment 9. 



36. Same, lateral view of the 9th sternum, showing the large copulatory 



process (cps). 



Plate V. 

 (Grylloidea and Tridactyloidea). 



37. Gryllus assimilis (Fabr.). (Grylloidea). Dorsal view of separated penis, 



ventral lobes omitted. The integument is cut through just m front of the 

 pseudosternite. 



38. Same, ventral view of penis, the free parts of the ventral lobes cut offin order 



to show the spermatophore sac and structures underlymg the 

 pseudosternite. 



39. Same, lateral view of separated penis; potash preparation. 



40. Same, postero-ventral view of genitalia of last nymphal stage. 

 4L Same, ventral view of genitalia of last nymphal stage. 



42. Nemobius fasciatus (DeGeer). (Grylloidea). Dorsal view of separated 



genitalia. The anterior, lighter part of the pseudosternite hes beneath the 

 outer integument. The ventral lobes are represented as showing through 

 from above. 



43. Same, ventral view of genitalia. 



*sv, in Figs. 30 and 3L 



