This large group of hymenoptera includes those groups which have no constriction between the thorax and the abdomen, are at least 2.5 mm. in length and have a several areas of their wings completely enclosed by veins.  Their English name sawflies is a reference to the saw-like process which projects from the end of the abdomen in females, used to cut into vegetation to insert eggs.

A key to identify the different superfamilies in the group found in Britain is found below.  

The second file illustrates the morphology of the structures of the thorax in sawflies viewed from the side.  This would be of use to workers in any part of the world.