This variety is associated with the Buck-Toothed Eagle family. All examples are known struck on billon planchets. This family is notorious for having typically ugly coins - either they were produced with poor details or most just survive that way. Surviving population for this variety is between 10 and 15 documented examples.
 
This example is quite nice for this variety with F/VF details albeit from a weak strike makes this look more like a VG or thereabouts. Some surface marks, but nothing crazy for a 180+ year old piece.