That's a nice looking fly, and it's different from the Semper Fli in Pop Fleyes
. To compare, the pattern in the book has a tail of 6 to 8 saddle hackles tied "in the round", and the head is a pair of webby hackles wound forward Seaducer style.
Come to think of it, I think he's now calling this the Semper Fleye, so maybe the newer name indicates that this is a more recent tweaking of the pattern. Either way, using this pattern in black and at night can't be a bad thing.