There are approximately 30-35 species in the genus and at least a few undescribed species are known to be present in museum collections. The genus consists of four subgenera, Synagris , Paragris, Pseudagris and Rhynchagris.
The most notable morphological features occur in large males of the subgenera Synagris and Paragris. S. (S.) cornuta (photograph at top left), one of the most common and widespread of wasps in central and west Africa, displays two mandibular "tusks" in large males, the size of the tusks correlated with the size of the male (but only in larger males). A closely related species, S. (S.) proserpina , has similar structures though these appear slightly more robust. This species replaces S. cornuta in east Africa. The third species in the subgenus, S. fulva, is one of the most bizarre wasps I have ever seen. It has two relatively flimsy mandibular "tusks" which curve outwards (in contrast to those in S. cornuta and S. proserpina) and a third, clypeal, "horn" which arcs forward from the centre of the clypeus (photo, top right). I have seen specimens of large males which resemble S. fulva, but in which only one large clypeal horn is present. These males almost certainly belong to an undescribed species.
Species of Synagris
The genus Synagris includes the following 28 described species: