In the Phasmidæ, in Anabrus, and in the Odonata the cercopods, which are not jointed, are converted into claspers, and in the Odonata the claspers are spiny within, so as to give a firmer hold. The suranal plate is apparently so modified as to aid in grasping the female. In nearly all the Trichoptera there are, besides the suranal plate, which is sometimes forked (Nosopus), a pair of superior and of inferior claspers, and in certain genera (Ascalaphomerus, Macronema, Rhyacophila, Hydropsyche, Amphipsyche, Smicridea, and Ganonema) the lower pair are 2–jointed like those of Ephemeridæ. The number of abdominal segments in the adult Trichoptera is nine, and McLachlan states that the genital armature consists of three pairs of appendages, _i.e._ a superior, inferior, and intermediate pair, besides the suranal plate (vestige of a tenth segment) and the penis. Judging by his figures, these three pairs of appendages arise from the last or ninth uromere, and the upper pair seem to be the homologue of the cercopoda of ephemerids. It needs still to be ascertained whether the intermediate pair is a separate set, or merely subdivisions of the upper or lower, and whether one of the latter may not arise from the penultimate segment, because we should not expect that the last segment should bear more than one pair of appendages, as we find to be the case in arthropods in general, and in the Neuroptera, from which the Trichoptera may have originated. [Illustration: FIG. 199.—End of abdomen of embryo of Mantis: _r_, rhabdopod; _c_, cercopod; _sp_, suranal plate; _st_, stigma on 8th segment.—After Heymons. ] [Illustration: FIG. 200.—End of abdomen of _Periplaneta americana_, ♂, side view: _c_, cercopod; _st_, stilus; _p_, penis; _t_, titillator; _d_, “bird’s head” (clasper?); _i_, “oblong plate”; IX-XI, terminal segments; X, suranal plate; XI′, 11th sternite.—After Peytoureau. ] In most larvæ of the Trichoptera, especially the Rhyacophilidæ and Hydropsychidæ, the last abdominal segment bears a pair of 2–jointed legs (cercopoda), ending in either one or two claws, which under various forms, sometimes forming long processes, persist in the pupa; and there appears to be a suranal plate, the vestige of the tenth uromere. In the pupa, judging by Klapálek’s figure of Leptocerus (24_{8,9}, 25), a pair of lateral spines arise which may in the imago form one of the pairs of appendages or styles. In the pupa of _Œcetis furva_ his figure 28_{9} shows two pairs of 1–jointed appendages arising from the last segment; whether the long dorsal or upper styles arise from the vestige of a more distal segment is not distinctly shown in Klapálek’s sketch. The origin of these elements of the genital armature evidently needs further study.