=The styles and genital claspers= (_Rhabdopoda_).—Other appendages of the end of the abdomen of pterygote insects, and generally, if not always, arising from the ninth segment, are the clasping organs, or _rhabdopoda_ as we may call them, of Ephemeridæ (Fig. 197), Neuroptera (Corydalus [Fig. 198], Myrmeleon, Rhaphidia), Trichoptera, Lepidoptera, Diptera, and certain phytophagous Hymenoptera. They do not appear to occur in insects which are provided with an ovipositor. In Thysanura the styles are present on segments 1–9 (Fig. 179). Those of the male Ephemeridæ, of which there are two pairs arising from the ninth segment, are remarkable, since they are jointed, and they serve to represent or may be the homologues of two of the pairs of stylets composing the ovipositor of insects of other orders. The lower pair (Fig. 197, _rh_) are either 2–, 3–, or 4–jointed (in Oniscigaster 5–jointed), while those of the upper pair are 2–jointed (_rh′_). These rhabdopods in the ephemerids are evidently very primitive structures, since they approach nearest in shape and in being jointed to the abdominal legs of Scolopendrella and the Myriopoda. The styles of the Orthoptera are survivals of the embryonic appendages of the ninth segment (Wheeler, etc.). In Mantis they are seen to have the same relations as the cerci, as shown by Heymons (Fig. 200). [Illustration: FIG. 197.—Abdomen of _Ephemera_ (Leptophlebia) _cupida_, ♂: _c_, base of cercopoda; _rh_, outer 3–jointed claspers or rhabdopods; _rh′_, inner pair. _A_, side view. ] [Illustration: FIG. 198.—End of abdomen of _Corydalus cornutus_, ♂: _vh_, rhabdopod; _c_, cercopod. ]