Electroconvection cells at fluid/fluid interfaces may be part of a general pattern which includes convection cells driven by thermal energy transport and those driven by chemical potential transport. Interfacial tension appears to be the unstable parameter in each case. Electroconvection cells were generated in thin layers of eight different isotropic dielectric liquids by bombarding the liquid/air interface with negative corona. The same electroconvection cells formed and followed the same sequence of development in each liquid. Three types of electroconvection cells were found, each being a ring vortex of liquid but with differing sizes and rotations. Increasing current density was accompanied by decreasing diameters of types II and III cells, and by a gradual large increase in total surface area resulting from the nature and behaviour of type II cells which form open channels penetrating entirely through the liquid layer. The vertex angle for II cell cones frozen in a thermoplastic recording compared favourably with a limiting value suggested by Taylor (1964) who may have measured II cell vertices in experiments which obscured cellular motion.