Looks to be a Danish M1915 long bayonet. I like the look of them!

Learning what I can, but someone will come around with more info for you.

 

I found more info on the shorter version of this.....not alot about this one.

 

It's a Danish M1915 bayonet complete with scabbard in decent shape, but missing the leather frog to attach it to the belt. These were adopted early in WW1 as the Danes sought to counter the German "tactic" (real or imagined) of charging into battle with their packs slung on their chests to increase standoff distance in case they took a bayonet. These were issued for both long rifles and carbines moving forward in place of the short 1889/93 bayonets

When they pop up on eBay, I tend to see them sell for between $175-225 based on condition.