Here is a bit about the originator of the Funnel Dun fly I found on the web:
The Funnel DunThe simplest version of an upside down dun fly was created by Niel Patterson as the ?funnel dun?, this pattern uses the same hackle as regular Catskill tied or Halfordian creations, but it is forced into a cone or funnel shape, combined with the tail being tied markedly around the bend of the hook the fly has a distinct propensity to land ?the wrong way up? thereby ?hiding the hook point?. It is certainly much simpler to manufacture than Goddard and Clarke?s pattern, but I have to confess it lacks aesthetic appeal to my eye. (I have a soft spot for fishing with pretty looking flies I?m afraid).