(after Fletcher 2009 and updates): The Horned Treehoppers are characterised by the enlargement of the pronotum, sometimes into grotesque shapes. In Australian species there are usually two lateral horns but these are often reduced to bumps and sometimes missing altogether.
Fletcher MJ
(2009):
Identification keys and checklists for the leafhoppers, planthoppers and their relatives occurring in Australia and neighbouring areas (Hemiptera: Auchenorrhyncha). WEB