A traditional english mint flavoured hard sugar confection. To be the real mint humbug, must have black-and-white stripes running from one end of the lozenge to the other.

The difference (apart from the appearance) between these and murray mints is that murray mints have a slight buttery flavour that these lack. Humbugs also tend to have a chewy centre (still minty, still sugary), as well (which murray mints don't).

Thanks to Albert Herring for reminding me about the chewy bits