 They are typically glossy, dark, smooth wasps with somewhat compressed bodies and somewhat reduced wing venation.It is common for various metasomal segments to be fused in various ways (often diagnostic for families or subfamilies), and the petiole is very short, when present.With the exception of the Cynipidae (the gall wasps), it is a poorly known group as a whole, though there are nearly 3000 known species in total, and a great many species are still undescribed, mostly in the Figitidae.