Melodia pants were once seen as the ultimate Tribal belly dance pants. There are many imitators now and you'll probably find a few on the Tribal bellydance pants page.
Melodia is a small company so their designs are at a premium, and it's rare to find their pants being sold by anyone else - if I've managed to find any, they'll be listed below.
If you want to splash out, I recommend Melophoenix belly dance pants, the result of a collaboration between Melodia and Phoenix Rising. They have the classic Melodia shape with artwork on the flares, like the peacock pants in this pic.
Melodia pants on eBay