none In Pamphiliidae radix of IX gonapophysis is quite large than the laminium and each IX gonocoxite bears a two segmented gonostylus. In Xyelidae the radix and laminium are almost equal and the gonostylus is single segmented. In Agridae, Cimbicidae, Diprionidae and Tenthredinidae the radix is smaller than laminium. In Cephidae the gonostyli are fused with the IX gonocoxites. In Xiphydridae and Siricidae the IX gonapophyses form a hollow, elongated needle like structure that resembles the same in apocritans. The furcula is well developed in Siricidae, but its two arms are not fused dorsally. Similar conditions prevail in Chalcidoidea. In Ichneumonoidea furcula is inverted V shaped structure. In Chrysididae structures are similar but mode of functioning differs. In Scoliidae and Sphecidae the furcula is inverted Y shaped and IX gonocoxite is divisible into three regions. General morphology; Appendages; Reproduction; Reproductive system; Evolution; Evolutionary adaptation Hymenoptera; Gonopod; Gonocoxite structural modifications; Gonapophyses; Structural modifications; Evolutionary trends; Gonocoxite & gonapophyses structural modifications