How can I setup a Material in Cycles for Z-Transparency? After converting to nodes in order to render using Cycles I've no idea where to enable the z-transparency. I guess the image textures alpha channel needs to be pluged somewhere but I've no idea which node would be suitable. 

The question is how could I correctly setup the nodes to have the same effect as when using z-transparency in BI? 




The materials original settings for BI are:



Which renders like:



I had no luck with DarenWs suggestion:
Use a Mix shader as the last node before the Material Output.   feeding it the hair material (diffuse shader or whatever) in the lower input, a Transparency shader in the upper, and the image texture's alpha into the Mix's "fac" input.