The morphology, function and phylogenetic significance of the hymenopterous ovipositor, as revealed by transverse sections, is explored. Ovipositors (including stings) of > 240 species belonging to some 69 families (representing all superfamilies) have been prepared and examined, and almost 180 are illustrated. Particular attention is paid to Ichneumonoidea. Sections show many new, phylogenetically informative characters as well as providing further insight into ovipositor function. Examples of synapomorphies are given which suggest various groupings at the family or subfamily levels. Functional interpretations are given for several characters, with particular reference to substrate penetration, passage of the egg along the ovipositor and stinging.

Detailed venom reservoir and venom gland intima morphology has been investigated in reprsentatives of 84 genera and 10 subfamilies of Braconidae with particular reference to the Doryctinac, basal cyclostomes and related groups including the Opiinae, Alysiinae and Rogadinae sens. lat. Several new phylogenetically significant characters are described and illustrated. Extcnsivc secretory ductules on the primary venom duct is suggested as a synapomorphy for the subfamilies Braconinac, Doryctinae, Opiinae, Alysiinae and Gnamptodontinae. The presence of two separate venom gland insertions and their position beyond the spiral sculpture of the reservoir are suggested as synapomorphies for the subfamilies Doryctinae and Ypsistocerinac. An anterior, weakly sclerotized, probably glandular. expansion of the reservoir characterizes the Histeromerinae and Rhyssalinae and also the enigmatic genera Thoracoplites Fischer and Doryctomorpha Ashmead which are hcre transferred to the Rhyssalinae. Within the Doryctinac, venom reservoir morphology suggests three generic groups, one comprising the genera of the Odontohraconini and possibly also the genera Acanthodoryctes, Binareu and Monarea, all of which have an essentially undivided reservoir with extremely fine and uniform spiral sculpture. the second comprising the genera Doryctophasmus, Euscelinus, Gildoria, Halycea and Schlettereriella, which share horn‐like processes at the base of the venom duct insertions, and a third including Acrophasmus. Dendro‐ soter, Heterospilus, Megaloproctus, Rutheia, Paraspathius, Schlettereriella. Spathius and Syngaster based on the presence of two markedly different densities of annulation of the reservoir. The degree to which external and other characters support these groups is discusscd.