It is a great looking fly, I am going to tie some up as sea-trout flies (sea-run browns), but as usual the idea of the reverse hackle is not new.
Anglers in the Alpine districts of Italy and France were tying their own versions over two hundred years ago.
Here is one I tied a few years ago, I never really got the chance to test it out properly, they were tied for use on fast running mountain streams.




for more info have a look at
http://www.dtnicolson.dial.pipex.com
Go to "Alpine Spiders" on the index page, there are four pages.

There are a lot of modern Italian versions by Walter Bartellini shown on the pages as well as the three I tied. He used modern nylon thread, I prefer Pearsalls silk myself. They were taken from W. H. Lawries book on International Trout Flies.